late 15c., "speech, discourse, conversation," from talk (v.). Meaning "informal lecture or address" is from 1859. Meaning "a subject of gossip" is from 1620s (in talk of the town). Talk show first recorded 1965; talk radio is from 1985.
adjective suffix, "full of or characterized by," from Old English -ig, from Proto-Germanic *-iga- (source also of Dutch, Danish, German -ig, Gothic -egs), from PIE -(i)ko-, adjectival suffix, cognate with elements in Greek -ikos, Latin -icus (see -ic). Originally added to nouns in Old English; used from 13c. with verbs, and by 15c. even with other adjectives (for example crispy).