Show popular animal featured in stamp (8)
I believe the answer is:
Here is my best explanation:
'show' is the definition.
('indicate' can be a synonym of 'show')
'popular animal featured in stamp' is the subsidiary indication.
'popular' becomes 'in'.
'animal' becomes 'cat' (I've seen this in other clues**).
'featured in' indicates putting letters inside.
'stamp' becomes 'die' (I've seen this in other clues).
'cat' inserted within 'die' is 'dicate'.
(Other definitions for indicate that I've seen before include "Point out, make known", "Point, show, signal", "(Give a) signal", "Point out, suggest", "Signal or point to", "Show, point", "Point out or give some notion of" and "Make a signal".)