Material used for hose is now primarily plastic only (5)
I believe the answer is:
nylon
'material used for hose' is the definition.
(material used in hosiery)
'now primarily plastic only' is the wordplay.
'primarily' indicates taking the first letters.
'plastic' indicates an anagram (plastic can mean easily moulded).
The first letter of 'now' is 'n'.
'only' is an anagram of 'ylon'.
'n'+'ylon'='NYLON'
'is' acts as a link.
(Other definitions for nylon that I've seen before include "may be damaged by running" , "Fibre of polymeric amides" , "Man-made material" , "Artificial material" , "Synthetic cloth" .)