How to say friend in Japanese?

Friend in Japanese: 友 /to mo/

友達 /to mo da chi/

ダチ /da chi/ (informal, spoken language)

ダチ公 /da chi kou/ (very colloquial)

友人 /yuu jin/ (close friend, buddy)

親友 /shin' yuu/ (best friend, intimate friend, close friend)

益友 /e ki yuu/ (profitable friend, useful person/friend etc)