Still, in strange sense, showing indifference (15)

'indifference' is the definition.
(synonyms)

'still in strange sense' is the wordplay.
I cannot quite understand how this works, but
'still' could be 'motionless' (synonyms) and 'motionless' is located in the answer.
an anagram of 'sense' is 'eness' which is present in the left over letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).

'showing' is the link.

Can you help me to learn more?