Walk pram over first time (5)
I believe the answer is:
tramp
'walk' is the definition.
(tramp is a kind of walk)
'pram over first time' is the wordplay.
'over' indicates anagramming the letters.
'first' means one lot of letters go next to another.
'time' becomes 't'.
'pram' anagrammed gives 'ramp'.
'ramp' after 't' is 'TRAMP'.
(Other definitions for tramp that I've seen before include "Walk with heavy steps like hobo" , "Ship, possibly" , "Lady or gentleman of the road or roving ship" , "A boat; a vagrant" , "Merchant ship" .)