Suitable for holding (7)

I believe the answer is:

tenable

I'm a little stuck... Click here to teach me more about this clue!

'suitable for holding' is the definition.
Both the answer and definition are adjectives. Maybe there's an association between them I don't understand?

This is the entire clue.

Can you help me to learn more?

(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.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.