Measure some lime trees (5)
I believe the answer is:
metre
'measure' is the definition.
(I know that measure can be written as metre)
'some lime trees' is the wordplay.
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'METRE' is hidden within 'lime trees'.
(Other definitions for metre that I've seen before include "determined by scanning" , "Approx 39 inches" , "Beat pattern (mus.)" , "measure of length" , "Alignment of feet determines such" .)