Press one deviously for an answer (8)
I believe the answer is:
response
'an answer' is the definition.
('response' can be a synonym of 'answer')
'press one deviously' is the wordplay.
'deviously' indicates an anagram (I've seen this in other clues).
'press'+'one'='pressone'
'pressone' is an anagram of 'RESPONSE'.
'for' acts as a link.
(Other definitions for response that I've seen before include "Preens so by way of answer" , "Rejoinder, retort" , "Reaction, reply" , "Sees porn (anag) - answer" , "Answer - retort" .)