Springy hat worn by English non-smoker (7)
I believe the answer is:
tensile
'springy' is the definition.
(both can mean stretchy)
'hat worn by english non-smoker' is the wordplay.
'hat' becomes 'tile' (I've seen this before).
'worn by' indicates putting letters inside (I've seen this in other clues).
'english' becomes 'E' (abbreviation).
'non-smoker' becomes 'NS' (medical abbreviation).
'e'+'ns'='ens'
'tile' placed around 'ens' is 'TENSILE'.
(Other definitions for tensile that I've seen before include "Capable of being drawn out or stretched" , "Capable of stretching" , "Relating to stress" , "Relating to tension" , "Able to be stretched" .)