Problem with fool replacing oxygen in space (6)
I believe the answer is:
hassle
'problem' is the definition.
(I've seen this before)
'fool replacing oxygen in space' is the wordplay.
I cannot quite see how this works, but
'fool' could be 'ass' (both can mean a stupid person) and 'ass' is located in the answer.
This explanation may well be incorrect...
'with' acts as a link.
Can you help me to learn more?
(Other definitions for hassle that I've seen before include "Harass; pester" , "Informally annoy or bother" , "Harass - grief" , "Annoy persistently" , "Annoy continually" .)