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]
(..) Well I'm not telling, acting captain. What? What now? That doesn't frustrate you, does it? My lack of cooperation, that doesn't make you angry? - Are you a member of Starfleet? - Um... yes. Can I get a towel? Under penalty of court martial I order you to explain to me... (..)2009 Star Trek