Gets at big-top among the stately ones? (7)

'gets' is the definition.
The definition and answer can be both related to change as well as being verbs in their -s form.
Perhaps you can see a link between them that I can't see?

'at big-top among the stately ones?' is the wordplay.
'at' says to put letters next to each other.
'big-top' becomes 'b' (top of the word 'big-').
'among' means one lot of letters goes inside another.
'the stately' becomes 'noble' (I've seen this before).
'ones?' becomes 's' (I can't explain this - if you can you should give a lot more credence to this answer).
'b' inserted into 'noble' is 'nobble'.
'nobble' next to 's' is 'NOBBLES'.

Can you help me to learn more?