Salt and ice combination extensively used (7)
I believe the answer is:
elastic
'extensively used' is the definition.
The answer and definition are not the same part of speech. However, past participle verbs and adjectives occasionally mean the same thing.
'salt and ice combination' is the wordplay.
'and' says to put letters next to each other.
'combination' indicates an anagram.
'salt' after 'ice' is 'icesalt'.
'icesalt' is an anagram of 'ELASTIC'.
Can you help me to learn more?
(Other definitions for elastic that I've seen before include "Laciest (anag.)" , "Able to stretch" , "Kind of band" , "Stretch material" , "Like a small band" .)