Bachelor's left with lots of ale and rum (4)
I believe the answer is:
eery
'rum' is the definition.
(both can mean 'strange')
'bachelor's left with lots of ale' is the wordplay.
'bachelor' becomes 'b' (abbreviation e.g. BA=Bachelor of Arts).
'left' suggests deleting specific letters.
'with lots of ale' becomes 'beery'.
'beery' with 'b' taken away is 'EERY'.
'and' is the link.
(Other definitions for eery that I've seen before include "Weirdly frightening" , "Weird" , "Strangely frightening" , "Strange" , "Spooky" .)