Tremble with cold (6)
I believe the answer is:
shiver
'tremble with cold' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for shiver that I've seen before include "Shake with cold; splinter" , "Tremble from cold or with fear" , "Shake (with cold, excitement etc)" , "Shake uncontrollably" , "Tremble, shatter" .)