In some foreign educational systems, the term for thesis or dissertation is modified by the name of the degree. I can't immediately think of systems where there are separate words for thesis and dissertation like in the US, where I would say honors thesis (undergrad), masters thesis, but either doctoral/PhD thesis or doctoral /PhD dissertation. To me, thesis could mean any final degree project requirement (but not a course term paper) while dissertation specifically means doctoral or even PhD.

In French, for instance, one would say these de troisieme cyiecle (accents are missing and spelling looks wrong?) for a sort of graduate degree that might (I'm sure some would disagree) be considered between a MA/MS and PhD, and these d'etat (accents missing) for a higher level doctorate, but then aggregation or habilitation for the very high-level (in principle) major thesis that qualifies one to become a full professor. (The systems depend on the field and are evolving; in some academic areas, it's more of a competitive oral exam by a national committee.) In some French-speaking countries, a full professor is referred to as an ordinaire.

In German, one has the diplomarbeit (literally work or homework preceded by the title of the degree, usually translated as just diploma) for the traditional first degree which is considered roughly a MA/MS and doctorarbeit for the PhD. This is followed by the habilitation and the award of the venia legendi (Latin words) or right to teach. The latter, which could be viewed as equivalent to the standards for tenure, is expected for the equivalent of Associate Professor or Full Professor positions, although "equivalence" can sometimes be successfully argued, especially for foreigners. By the way, in German, an associate professor is called an extraordinary professor, while a full professor is an ordinary professor.

The systems are evolving as a result of the "Bologna Accords" which standardize European univesity education (in the part of Europe that agreeed to these reforms, roughly the EU) to an initial three-year degree (to be on the level of a US BA/BS but perhaps more specialized), followed by a two-year graduate degree based largely but not totally on further coursework, and then a research-based PhD (ideally in several more years). As in the US, different universities and departments have different standards.