Exclamation of annoyance when daughter meets rodent (4)
I believe the answer is:
drat
'exclamation of annoyance' is the definition.
(I've seen this before)
'daughter meets rodent' is the wordplay.
'daughter' becomes 'd'.
'meets' says to put letters next to each other.
'rodent' becomes 'rat' (rat is a kind of rodent).
'd'+'rat'='DRAT'
'when' is the link.
(Other definitions for drat that I've seen before include "Exclamation of annoyance" , "Bother" , "Blow!" , "Curse it!" , "blast" .)