adjective
1.
beyond any doubt or ambiguity
a decided advantage over her opponent
Synonyms: assured, clear-cut, definite, pronounced
Related Word: determined, resolved; certain, positive, sure; categorical, explicit, express, unequivocal; clear, obvious, runaway, unmistakable
Contrasted words: doubtful, dubious, problematic, uncertain; equivocal, obscure, vague
Antonyms: questionable
2.
free from doubt or wavering
he had a decided manner
Synonyms: bent, decisive, determined, intent, resolute, resolved, set, settled
Related Word: certain, cocksure, positive, sure; iron-jawed; established, fixed; earnest, purposeful, serious; unfaltering, unhesitating, unwavering
Contrasted words: doubtful, dubious, irresolute, uncertain; faltering, hesitant, vacillating, wavering; undetermined, unresolved, unsettled, unsure
Antonyms: undecided
3.
Synonyms: positive 1, categorical, definite, unequivocal