It is not in the least ambiguous. Perhaps you'll find this more enlightening:

"Airport screenings of passengers and their baggage constitute administrative searches and are subject to the limitations of the Fourth Amendment. United States v. Davis, 482 F.2d 893, 908 (9th Cir.1973) (noting that airport screenings are considered to be administrative searches because they are “conducted as part of a general regulatory scheme” where the essential administrative purpose is “to prevent the carrying of weapons or explosives aboard aircraft”); see also id. at 895, 904. Thus, airport screenings must be reasonable. See Torbet v. United Airlines, Inc., 298 F.3d 1087, 1089 (9th Cir.2002). To judge reasonableness, it is necessary to balance the right to be free of intrusion with “society's interest in safe air travel.” United States v. Pulido-Baquerizo, 800 F.2d 899, 901 (9th Cir.1986)."

In Davis and its progeny, we have established a general reasonableness test for airport screenings. “An airport screening search is reasonable if: (1) it is no more extensive or intensive than necessary, in light of current technology, to detect weapons or explosives; (2) it is confined in good faith to that purpose; and (3) passengers may avoid the search by electing not to fly.” Torbet, 298 F.3d at 1089 (citation omitted); see also Davis, 482 F.2d at 913; Pulido-Baquerizo, 800 F.2d at 901.

. . .

We have previously found airport screenings which require passengers to walk through a magnetometer and submit carry-on luggage for x-ray screening to be reasonable. See, e.g., United States v. Doran, 482 F.2d 929, 932 (9th Cir.1973); Pulido-Baquerizo, 800 F.2d at 901-02; Torbet, 298 F.3d at 1089-90. Generally, such a search “is brief, is less intrusive than the typical search warrant execution, does not have a stigma attached to it, is not made by armed police, and is often made only with advance notice.” Lafave, supra, § 10.6(c) [emphasis mine].

U.S. v. Marquez, 410 F.3d 612, C.A.9 (Wash.),2005.

You also might find this interesting, establishing a hierarchy of intrusiveness for airport searches:

Third, the procedures involved in Hartwell's search were minimally intrusive. FN10 They were well-tailored to protect personal privacy, escalating in invasiveness only after a lower level of screening disclosed a reason to conduct a more probing search. The search began when Hartwell simply passed through a magnetometer and had his bag x-rayed, two screenings that involved no physical touching. See United States v. Slocum, 464 F.2d 1180, 1182 (3d Cir.1972) (an airport magnetometer screen “per se is justified”). Only after Hartwell set off the metal detector was he screened with a wand-yet another less intrusive substitute for a physical pat-down. And only after the wand detected something solid on his person, and after repeated requests that he produce the item, did the TSA agents (according to Hartwell) reach into his pocket.

U.S. v. Hartwell, 436 F.3d 174 C.A.3 (Pa.),2006

There is also this, from the same case:

In addition to being tailored to protect personal privacy, other factors make airport screening procedures minimally intrusive in comparison to other kinds of searches. Since every air passenger is subjected to a search, there is virtually no “stigma attached to being subjected to search at a known, designated airport search point.” See United States v. Skipwith, 482 F.2d 1272, 1275 (5th Cir.1973).

Think about how that applies to "random" gate screenings.

Here's some more:

Headnote Citing References Routine security searches at airport checkpoints pass constitutional muster *110 because the compelling public interest in curbing air piracy generally outweighs their limited intrusiveness. See, e.g., United States v. Pulido-Baquerizo, 800 F.2d 899, 902 (9th Cir.1986); cf. United States v. Ferrer, 999 F.2d 7, 9 (1st Cir.1993) (upholding warrantless search of checked luggage on alternate ground of “abandonment,” but faulting government's “falling-domino approach, by which each intrusion diminishes privacy expectations enough to permit further infringements”). Consequently, all carry-on luggage can be subjected to initial x-ray screening for weapons and explosives without offending the Fourth Amendment. In the event the initial x-ray screening is inconclusive as to the presence of weapons or explosives, the luggage may be hand-searched as reasonably required to rule out their presence. Pulido-Baquerizo, 800 F.2d at 902.

[4] Headnote Citing References Other contraband inadvertently discovered during a routine checkpoint search for weapons and explosives may be seized and introduced in evidence at trial even though unrelated to airline security. See, e.g., Skipwith, 482 F.2d at 1277-78. On the other hand, lawful airline security searches of carry-on luggage may not be enlarged or tailored systemically to detect contraband ( e.g., narcotics) unrelated to airline security. See, e.g., United States v. $124,570 U.S. Currency, 873 F.2d 1240, 1243-45 (9th Cir.1989) (upholding suppression of contraband unrelated to airline security where screeners were rewarded monetarily by law enforcement authorities for detecting such contraband in carry-on luggage).

U.S. v. Doe, 61 F.3d 107, C.A.1 (Puerto Rico),1995.

The concerns, expressed in this circuit and elsewhere, that administrative searches not become a tool for law enforcement, reflect the limited rationale supporting those searches. To sustain a warrantless search, a court must normally make a case-specific factual determination that an exception to the warrant requirement (e.g. exigent circumstances, plain view) is applicable. If the search is approved, the approval covers that case only. An administrative search is different. By approving a warrantless search under this rationale, a court places its stamp of approval on an entire class of similar searches. Because it must consider the general, long-term implications of approving a new type of administrative search, the court will focus on legislative facts-those applicable to the entire class of cases-rather than adjudicative facts-those applicable only to the case before it. The court then relies on these legislative facts to make a dual determination: (1) that the search serves a narrow but compelling administrative objective, see, e.g., Camara v. Municipal Court, 387 U.S. 523, 536-37, 87 S.Ct. 1727, 1734-35, 18 L.Ed.2d 930 (1967); and (2) that the intrusion is as “limited ... as is consistent with *1245 satisfaction of the administrative need that justifies [it].” Davis, 482 F.2d at 910.

[6] Headnote Citing References Once a type of search has been approved under this rationale, the court is freed from the need to make a specific factual inquiry in every subsequent case. In later cases, the search is deemed proper if it is covered by the approved rationale. By the same token, the court cannot sustain a subsequent search that differs in material respects from the search initially approved, as the same legislative facts may not be applicable.

[7] Headnote Citing References In Davis, we approved airport security searches based on the understanding that they would be limited to searches for guns or explosives, and that they would be no more burdensome than necessary to achieve that objective. So long as the government officials conducting the searches pursue a single-minded objective-air safety-the rationale of Davis works well: the searches will, almost by definition, be no more intrusive than is necessary to achieve air safety. Not so where FTS officials have other objectives in mind. We can then no longer rely on the same legislative facts that underlay the search we approved in Davis.

U.S. v. $124,570 U.S. Currency, 873 F.2d 1240, C.A.9,1989.

And not to belabor the obvious, but a definition is not "ambiguous" because you don't understand it. It is ambiguous only if it has legitimate alternate constructions.