Unwarranted; not justified or authorized; lacking proper warrant or justification.
From ā- prefix (meaning 'not' or 'un-' in some uses) + warrant (Old Norse 'varandi,' past participle of 'vara,' meaning 'to guarantee'). The prefix negates the sense of justification.
English once used 'a-' as a negativizing prefix (like 'awanting'=lacking, 'awarrant'=unjustified), but we mostly abandoned this for 'un-' and 'in-'—these words are fossils of older grammar.
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