Gas from chicken -- nuts go dry inside (8)
I believe the answer is:
hydrogen
'gas' is the definition.
(I know that hydrogen is a type of gas)
'chicken nuts go dry inside' is the wordplay.
'chicken' becomes 'hen' (hen is a kind of chicken).
'nuts' indicates anagramming the letters (nuts can mean crazy).
'inside' means one lot of letters goes inside another.
'go'+'dry'='godry'
'godry' is an anagram of 'ydrog'.
'hen' placed around 'ydrog' is 'HYDROGEN'.
'from' acts as a link.
(Other definitions for hydrogen that I've seen before include "Gaseous element" , "The commonest element" , "... ditto: symbol H" , "Combines chemically with oxygen to form water" , "The most abundant chemical element in the universe" .)