Female runs American Corporation, part of a solid foundation (7)

I believe the answer is:

frustum

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'part of a solid foundation' is the definition.
'frustum' can be an answer for 'part' (I have seen 'part of cone' mean 'frustum' so perhaps 'part' could also mean 'frustum'). I am unsure of the 'of a solid foundation' bit.

'female runs american corporation' is the wordplay.
'female' becomes 'f' (abbreviation).
'runs' becomes 'r' (cricket abbreviation).
'american' becomes 'us'.
'corporation' becomes 'tum' (I've seen this before).
'f'+'r'+'us'+'tum'='FRUSTUM'

Can you help me to learn more?

(Another definition for frustum that I've seen is " part of cone".)

I've seen this clue in The Independent.

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