Owing to condensation, say (3)
I believe the answer is:
due
'owing' is the definition.
(similar in meaning)
'condensation say' is the wordplay.
'condensation' becomes 'dew' (dew is a kind of condensation).
'say' indicates a 'sounds like' (homophone) clue.
'dew' sounds like 'DUE'.
'to' acts as a link.
(Other definitions for due that I've seen before include "Deserved or unpaid" , "Proper, appropriate" , "Unpaid or expected" , "Outstanding" , "Expected, scheduled" .)