It will cover cuts made by small carrier (4)
I believe the answer is:
scab
'it will cover cuts' is the definition.
The definition suggests a singular noun which matches the answer.
'by small carrier' is the wordplay.
'by' says to put letters next to each other.
'small' becomes 's' (abbreviation - e.g. clothes size).
'carrier' becomes 'cab' ().
's' next to 'cab' is 'SCAB'.
'made' is the link.
Can you help me to learn more?
(Other definitions for scab that I've seen before include "Blackleg, strike-breaker" , "Crust that forms on a healing skin wound" , "Ignorer of strike" , "Blackleg - sign of injury" , "Crust forming over wound" .)