Needle that's four inches in length (4)
I believe the answer is:
hand
I believe this clue is a double definition.
'needle' is the first definition.
(thesaurus)
'that's four inches in length' is the second definition.
(hand is an archaic unit of measurement)
(Other definitions for hand that I've seen before include "Worker - penmanship - four inches" , "Limb extremity" , "Pointer; workman" , "Script" , "Manual worker" .)