Timid souls (4)
I believe the answer is:
mice
'timid souls' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for mice that I've seen before include "Small creatures in vermicelli" , "shy people" , "Tiny rodents" , "They'll play when the cat's away" , "Surfers click with these" .)