Emily Dickinson Lexicon

TEM-E-RA'RI-OUS, a. [Fr. temeraire; L. temerarius; from the root of time, tempest, – which see. The sense is rushing or advancing forward.]

1. Rash; headstrong; unreasonably adventurous; despising danger; as, temerarious folly. L'Estrange.
2. Careless; heedless; done at random; as, the temerarious dash of an unguided pen. Ray. [This word is not much used.]