Crossword Genius

Strengthen second locker wall (7)

Ross

I believe the answer is:

bolster

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

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

'second locker wall' is the wordplay.
I cannot really see how this works, but
'second' could be 's' (common abbreviation) and 's' is located in the answer.
The remaining letters 'bolter' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...

Can you help me to learn more?

(Other definitions for bolster that I've seen before include "Support - strengthen" , "Support; long pillow" , "Hold up" , "Prop up with long pillow" , "Extended pillow" .)

I've seen this clue in the Sydney Morning Herald.
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.