Similar words
mejilla
mejilla is the everyday, standard word for "cheek"; carrillo is more colloquial or regional, sometimes implying a chubby cheek.
Similar in other languages
German
Wange
Wange is the German word for the same thing — both mean "cheek."
Portuguese
bochecha
bochecha is the Portuguese word for the same thing — both mean "cheek."
Practice
1 What does carrillo mean?
cheek
2 Fill the gap: Infló los ___.
Full sentence: Infló los carrillos. (He puffed out his cheeks.)
3 Which fingerprint chart matches carrillo?
carrillo: neutral register, academic frequency, general domain, neutral connotation.