The American Heritage® Dictionary of the English Language, 4th Edition
adj. Presumptuously or recklessly daring: "I would never have been temerarious enough to make use of such a title on my own” ( Brendan Gill). See Synonyms at reckless.
Heedless or careless of consequences; unreasonably venturous; reckless; headstrong; inconsiderate; rash; careless.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. presumptuously daring
Word Usage
"It was a "temerarious" task to attempt to revive the types which, from the days of Harrison's _Essayists_, had occupied so many of the earlier illustrators."