Au*thor"i*ta*tive (?), a.
Having, or proceeding from, due authority; entitled to obedience, credit, or acceptance; determinate; commanding.
The sacred functions of authoritative teaching.
Having an air of authority; positive; dictatorial; peremptory; as, an authoritative tone.
The mock authoritative manner of the one, and the insipid mirth of the other.
-- Au*thor"i*ta*tive*ly, adv -- Au*thor"i*ta*tive*ness, n.
© Webster 1913.