They called it a comet, 'for lack of' a better term/word. [=because they could not think of a better term/word for it]
His honesty, or 'lack thereof', is the real problem. [=the real problem is his lack of honesty]
There was 'no lack of' interest in the proposal. [=there was much interest in the proposal]
(..) - You've no idea, the things I've done! And the answer is yes. - Without hesitation. - Even if there's another way? - There is no 'other' way. - You lack imagination. No, Stephen, you lack a spine. They're back. We have to end this. Now! Strange, get down here and fight! (..)2016 Doctor Strange