Boss with a cold: he finds problem (8)
I believe the answer is:
headache
'problem' is the definition.
(headache can mean a problem or annoyance)
'boss with a cold he' is the wordplay.
'boss' becomes 'head' (synonyms).
'with' says to put letters next to each other.
'cold' becomes 'c' (eg on taps).
'head'+'a'+'c'+'he'='HEADACHE'
'finds' acts as a link.
(Other definitions for headache that I've seen before include "Cause of worry or trouble" , "Serious problem?" , "Major problem" , "Severe problem" , "Problem, nuisance" .)