Hug one fan, that's sufficient! (6)
I believe the answer is:
enough
'sufficient' is the definition.
(similar in meaning)
'hug one fan' is the wordplay.
'fan' is an anagram indicator (I've seen 'fanned' mean this (I've seen this in other clues)).
'hug'+'one'='hugone'
'hugone' anagrammed gives 'ENOUGH'.
'that's' acts as a link.
(Other definitions for enough that I've seen before include "Sufficient to answer demand" , "As much as desirable" , "As much as necessary" , "To the required degree" , "Adequate amount to meet the purpose" .)