• to be at a loss for a topic
• to talk about, to talk of sg, to tell about
• to despair, to forego, forewent, foregone, to forgo, forwent, forgone, to give up, to go without sg, to lay down, to pass up, to relinquish, to write off
• to be unaware of sg, to be unwitting of sg
• to go into raptures over sg
• to account for sg, to give an account of sg, to render an account of sg, to yield an account of sg
• to give a lecture on sg, to lecture on sg