Father also included bear (5)
I believe the answer is:
Here is my best explanation:
'bear' is the definition.
'father also included' is the subsidiary indication.
'father' becomes 'pa' (pa is a kind of father).
'also' becomes 'and' (I've seen this before).
'included' means one lot of letters goes inside another.
'pa' placed around 'and' is 'panda'.
(Other definitions for panda that I've seen before include "Black and white mammal", "See 17", "Bamboo-eater", "Large black-and-white herbivorous mammal", "Asian animal", "Mammal, giant or red", "Endangered animal", "Beast", "Bearcat" and "Exotic animal".)