Mature crowd going north without loss (7)
I believe the answer is:
blossom
'mature' is the definition.
(I've seen this in another clue)
'crowd going north without loss' is the wordplay.
'crowd' becomes 'mob' (mob is a kind of crowd).
'going north' is a reversal indicator.
'without' indicates putting letters inside ('without' can be similar in meaning to 'outside').
'mob' backwards is 'bom'.
'bom' going around 'loss' is 'BLOSSOM'.
(Other definitions for blossom that I've seen before include "Grow" , "Mass of flowers - mature" , "May, possibly" , "Mature promisingly" , "Girl - flower(s)" .)