Strain last of lentils, if given time (4)
I believe the answer is:
sift
'strain' is the definition.
(I know that strain can be written as sift)
'last of lentils if given time' is the wordplay.
'last of' says to take the final letters.
'given' says to put letters next to each other.
'time' becomes 't' (abbreviation).
The last letter of 'lentils' is 's'.
's'+'if'+'t'='SIFT'
(Other definitions for sift that I've seen before include "Analyse carefully in fist" , "Examine (eg evidence) discriminatingly" , "Examine minutely" , "Distinguish as with a riddle" , "Remove lumps from, eg, flour" .)