Have just realised this a big issue for people on a MR, with multiple flights and lounge visits on the same day it becomes complicated to plan when to eat.
I think the AA definitions are a little vague and it's making it difficult to plan.
This thread could lead to a sticky/wiki article.
An extra data-point:
aa 1374 ORD MIA dep 1415 arr 1820
First Class Meal: Snack or brunch
From reading here it seems "Snack or brunch" could be a proper lunch or a cookie!