Dodo and emu, with time, possibly obsolescent (8)
I believe the answer is:
outmoded
'obsolescent' is the definition.
(thesaurus)
'dodo and emu with time possibly' is the wordplay.
'and' is a charade indicator (letters next to each other) (I've seen this in other clues).
'with' means one lot of letters go next to another.
'time' becomes 't'.
'possibly' is an anagram indicator.
'emu' after 't' is 'temu'.
'dodo' put after 'temu' is 'temudodo'.
'temudodo' with letters rearranged gives 'OUTMODED'.
(Other definitions for outmoded that I've seen before include "No longer fashionable" , "Dated" , "No longer in fashion" , "Old-fashioned" .)