When shadows are shortest (7)
I believe the answer is:
noonday
'when shadows are shortest' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for noonday that I've seen before include "heat?" , "Twelve a.m." , "Midday, 12p.m." , "Meridional" , "12 o'clock" .)