Chap on way to get some cows (4)
I believe the answer is:
herd
'some cows' is the definition.
(group of cows)
'chap on way' is the wordplay.
'chap' becomes 'he'.
'on' means one lot of letters go next to another.
'way' becomes 'rd' (short for road).
'he'+'rd'='HERD'
'to get' acts as a link.
(Other definitions for herd that I've seen before include "Drove" , "cattle together" , "A collection of livestock" , "Group of animals, cattle, say" , "pack" .)