Positive (8)
'positive' is the definition.
(similar in meaning)
This is all the clue.
(Other definitions for sure that I've seen before include "Certain to be a ruse" , "The old sewer" , "Completely certain" , "Certain, confident" , "certainly in the USA" .)
'positive' is the definition.
(I know that positive can be written as plus)
This is all the clue.
(Other definitions for plus that I've seen before include "The opposite of minus" , "sign of more to come" , "An advantage; positive" , "Advantage; also" , "An advantage (colloq.)" .)
'positive' is the definition.
(thesaurus)
This is the entire clue.
(Other definitions for absolute that I've seen before include "sure" , "Total; unqualified" , "Complete, total, without limits" , "Unlimited; not relative" , "Sheer, total, not limited" .)
(Other definitions for emphatic that I've seen before include "Forceful and definite" , "Direct" , "Categorical" , "Striking" , "Definite and clear" .)
'positive' is the definition.
(similar in meaning)
This is all the clue.
(Other definitions for certain that I've seen before include "Nice art (anag)" , "Absolutely sure" , "Decided" , "Particular" , "Assured" .)
'positive' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for can-do that I've seen before include "Positive" , "Positive-thinking" , "Showing willingness to get the job done" .)