Jack and Tom came back late, stumbling in (7)
I believe the answer is:
matelot
'jack' is the definition.
(thesaurus)
'tom came back late stumbling in' is the wordplay.
'came back' is a reversal indicator.
'stumbling' is an anagram indicator.
'in' indicates putting letters inside.
'tom' in reverse letter order is 'mot'.
'late' with letters rearranged gives 'atel'.
'mot' going around 'atel' is 'MATELOT'.
'and' is the link.
(Other definitions for matelot that I've seen before include "Sailor (slang from French)" , "A lot met (anag) - sailor" , "One at sea" , "seafarer" , "One sailor" .)