thanks so much to everyone. I stand corrected about meagre but think 9a a poor clue. Surely it should read abandon, present tense, not abandoned, past tense. Even then cast off has to do with boats not abandoning things.
cast off to reject; to release (hawks or hounds) in order to hunt or pick up a scent; to release (a boat) from its moorings; (in knitting, etc) to eliminate stitches by looping them together and removing them from the pins; to calculate the amount of printed matter that manuscript or keyed copy will make when typeset.
What do you think the past tense of cast off should be then, cheshunt? I think you will find the clue is quite correct.
3d TIPPET, 63d is LONGFIN I think not albacore, 82d EDAM. Think 10d probably is 'surpass'. I must have 15a wrong. I've got 'sparse' and my crossword solver has no solution for s?s?a?s if 9a is 'cast off'