Thanks Loge, I have 24 now but don't see what big becomes or how the definition works really.
A while ago I had tried LA plus centre of earth/apple, but can't find that word anywhere?
lumen - You'll find the def for 24d (last 8 words) in the 3 letter head word in Chambers and it justifies 'b?g'.
Also, 27 is in Chambers - but it's not 'core' (you need another fruit 'centre').