Make your mark in a very short time (4)
I believe the answer is:
tick
'mark in a very short time' is the definition.
'tick' can be an answer for 'mark' (I've seen this before). I'm not sure about the 'in a very short time' bit.
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for tick that I've seen before include "Blood-sucking mite or parasitic insect" , "Parasite, moment (colloq.)" , "Blood-sucking insect or sound of old clock" , "Little bloodsucker" , "Not cross" .)