Organic compound put into water gets egg producer extremely youthful (8)

'organic compound' is the definition.
(diphenyl is an organic compound)

'put into water gets egg producer extremely youthful' is the wordplay.
'put into water' becomes 'dip' (dip can mean to dunk into water).
'gets' means one lot of letters go next to another.
'egg producer' becomes 'hen' (hens produce eggs).
'extremely' suggests removing the centre (only the extremes of the word are used).
'youthful' with its middle taken out is 'yl'.
'dip'+'hen'+'yl'='DIPHENYL'