Slur like individual imbibing martini finally (9)
I believe the answer is:
aspersion
'slur' is the definition.
(synonyms)
'like individual imbibing martini finally' is the wordplay.
'like' becomes 'as'.
'individual' becomes 'person' (an individual person).
'imbibing' indicates putting letters inside (drinking in).
'finally' indicates one should take the final letters.
The last letter of 'martini' is 'i'.
'person' going around 'i' is 'persion'.
'as'+'persion'='ASPERSION'
(Other definitions for aspersion that I've seen before include "Slander" , "Malicious remark" , "No praises (anag) - disparaging remark" , "Attack on the character" , "Defamatory suggestion" .)