Eyelet can somehow produce gas (9)
I believe the answer is:
acetylene
'gas' is the definition.
(acetylene is a gas)
'eyelet can somehow' is the wordplay.
'somehow' indicates an anagram.
'eyelet'+'can'='eyeletcan'
'eyeletcan' with letters rearranged gives 'ACETYLENE'.
'produce' acts as a link.
(Other definitions for acetylene that I've seen before include "Illuminating stuff also used for joining" , "powers industrial torch" , "Flammable gas" , "Gas used chiefly in welding" , "cutting gas emission?" .)