Suitable for holding (7)

I believe the answer is:

tenable

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'suitable for holding' is the definition.
Both the answer and definition are adjectives. Maybe they are linked in a way I don't understand?

This is the entire clue.

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(Other definitions for tenable that I've seen before include "Viable" , "okay as regards defence" , "Based on sound reasoning or evidence" , "Able to be believed" , "Well-founded" .)

I've seen this clue in the Evening Standard.

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