After very short time, pastor abandoned defunct browser (11)
I believe the answer is:
triceratops
'defunct browser' is the definition.
(extinct browsing animal)
'after very short time pastor abandoned' is the wordplay.
'after' is a charade indicator (letters next to each other).
'very short time' becomes 'trice' (I've seen this before).
'abandoned' is an anagram indicator.
'pastor' is an anagram of 'ratops'.
'trice' next to 'ratops' is 'TRICERATOPS'.
(Other definitions for triceratops that I've seen before include "Extinct reptile" , "Three-horned dinosaur" , "Old creature" , "Cretaceous herbivore" , "Horned dinosaur" .)