Gone into stores with non-paying travellers (9)
I believe the answer is:
stowaways
'non-paying travellers' is the definition.
The definition and answer can be both people as well as being plural nouns.
Perhaps they are linked in a way I don't understand?
'gone into stores with' is the wordplay.
'gone' becomes 'away' (synonyms).
'into' indicates putting letters inside.
'stores with' becomes 'stows' ('stow' can be a synonym of 'store'. I am not sure about the 'with' bit.).
'away' put within 'stows' is 'STOWAWAYS'.
Can you help me to learn more?
(Another definition for stowaways that I've seen is " The hide aboard to get free passage".)