One might secure a bundle, at a stretch (7,4)
I believe the answer is:
elastic band
'one' is the definition.
Both the answer and definition are singular nouns.
Maybe you can see an association between them that I can't see?
'secure a bundle at a stretch' is the wordplay.
I cannot quite understand how this works, but
'a' could be 'an' and 'an' is found in the answer.
'stretch' could be 'elastic' (similar in meaning) and 'elastic' is found within the answer.
This explanation may well be incorrect...
'might' is the link.
Can you help me to learn more?
(Other definitions for elastic band that I've seen before include "Rubber ring" , "Office item" , "It's flexible" , "the papers may be gripped by?" , "Loopy item" .)