Carry child on end of knee (4)
I believe the answer is:
tote
'carry' is the definition.
(toting is a kind of carrying)
'child on end of knee' is the wordplay.
'child' becomes 'tot' (I've seen this before**).
'on' says to put letters next to each other.
'end of' suggests the final letters.
The last letter of 'knee' is 'e'.
'tot'+'e'='TOTE'
(Other definitions for tote that I've seen before include "Carry - betting system" , "Large bag" , "convey" , "Form of betting: carry" , "Drag; betting system" .)