WordNet sense 1 (a speech that is open to the public):

lecture, public lecture

WordNet sense 2 (idle gossip or rumor):

talk of the town

WordNet sense 3 (an exchange of ideas via conversation):

talking

WordNet sense 4 (use language):

speak

WordNet sense 5 (reveal information):

spill

WordNet sense 6 (express in speech):

mouth, utter, verbalize, verbalise, mouth

WordNet sense 7 (divulge confidential information or secrets):

babble, blab, peach, sing, tattle, spill the beans, babble out, blab out, let the cat out of the bag