Bird nesting in the hibiscus (4)
I believe the answer is:
ibis
'bird' is the definition.
(ibis is a kind of bird)
'nesting in the hibiscus' is the wordplay.
'nesting in' indicates the answer is hidden within the clue.
'IBIS' can be found hidden inside 'the hibiscus'.
(Other definitions for ibis that I've seen before include "Near-colourless mineral" , "Retreat" , "Sacred Egyptian bird" , "Storklike bird" , "Wading bird with a down-curved bill" .)