2250: Knavish
The unclued lights (one of two words, and one of three) when preceded by the same word (which has to be discovered) reveal words (in one case, a non-word which is almost a foot) or phrases all of which are listed in Brewer, with some also listed in Chambers. Ignore all hyphens. Across 7 Losing core of drive, rant and go off line (6) 11 Not starting continental deer, say, or veal dish (10) 13 Sudden increases of bitterns’ calls (5) 14 Employing you, I hear, even in espionage (5) 15 Sign away big business arrangement — there are the overheads!