Ache indoors, running to acquire figure (11)

I believe the answer is:

icosahedron

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'figure' is the definition.
(I've seen this before)

'ache indoors running' is the wordplay.
'running' indicates anagramming the letters.
'ache'+'indoors'='acheindoors'
'acheindoors' with letters rearranged gives 'ICOSAHEDRON'.

'to acquire' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.

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(Other definitions for icosahedron that I've seen before include "Twenty-faced solid" , "Figure" .)

I've seen this clue in The Daily Express.

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