Hot, steamy, lacking oxygen, turning violet (8)
I believe the answer is:
amethyst
'violet' is the definition.
Both the definition and answer are adjectives. Perhaps you can see an association between them that I don't see?
'hot steamy lacking oxygen turning' is the wordplay.
'lacking' suggests deleting specific letters.
'oxygen' becomes 'O' (O is the chemical symbol for oxygen).
'turning' indicates an anagram.
'hot'+'steamy'='hotsteamy'
'hotsteamy' with 'o' taken out is 'htsteamy'.
'htsteamy' anagrammed gives 'AMETHYST'.
Can you help me to learn more?
(Other definitions for amethyst that I've seen before include "Purple quartz, used as a gemstone" , "rock" , "Precious stone of purple quartz" , "February gemstone" , "Purplish gemstone" .)