This is the 1216th most frequent Portuguese word.
legais
"Legais" means "cool" or "legal" (in the sense of lawful).
Here, 'legais' is used as an informal adjective meaning 'cool' or 'fun', describing the quality of the movies.
Os filmes que vimos ontem eram muito legais.
The movies we watched yesterday were very cool.
In this sentence 'legais' functions as a formal adjective meaning 'legal', referring to the legality of actions and rules.
É importante seguir as regras legais em todas as situações.
It is important to follow the legal rules in all situations.
Again, 'legais' is used informally to describe positive qualities, emphasizing creativity or usefulness.