Dry in hothouse conditions (3)
I believe the answer is:
sec
'dry' is the definition.
('sec' can be similar in meaning to 'dry')
'in hothouse conditions' is the wordplay.
'in' says the answer is hidden in the clue.
'SEC' can be found hidden inside 'hothouse conditions'.
(Other definitions for sec that I've seen before include "'Dry, as wine (3)'" , "sort of function" , "21 down, as wine" , "(Of wines) dry" , "Dry wine perhaps" .)