Meaning

verb say something to someone that expresses praise

verb express congratulations

verb be proud of

originFirst attested in 1548; borrowed from Latin congrātulātus, the perfect active participle of Latin congrātulor (“to wish joy, rejoice (with); to congratulate”) (see -ate (verb-forming suffix)), from con- + grātulor, from grātus (“grateful, pleasing, agreeable, beloved”) + -or. By surface analysis, con- + gratulate.

Etymology from Wiktionary, CC BY-SA 3.0