An oaf at first implying Covid not very problematic — nut! (10)
I believe the answer is:
aficionado
'nut' is the definition.
(thesaurus)
'an oaf at first implying covid not very problematic' is the wordplay.
'at' says to put letters next to each other.
'first implying' becomes 'i' (1st letter of 'implying').
'not' is a deletion indicator.
'very' becomes 'v' (abbreviation).
'problematic' indicates anagramming the letters.
'an'+'oaf'+'i'+'covid'='anoaficovid'
'anoaficovid' with 'v' taken away is 'anoaficoid'.
'anoaficoid' is an anagram of 'AFICIONADO'.
(Other definitions for aficionado that I've seen before include "Fan (Sp.)" , "Admirer" , "lover" , "supporter" , "freak" .)