adj ·2 syllables ·Moderate ·High school level

Definitions

Adjective

1. 1
   uncertain, ambivalent.

   "I'm still unsure whether to attend the wedding."

2. 2
   unstable or precarious

   "unsure footing"

Adjective

1. 1
   lacking or indicating lack of confidence or assurance wordnet
2. 2
   lacking self-confidence wordnet

Synonyms

All synonyms

agnosticuncertainagnosticambiguousawkwardblankminded

Antonyms

All antonyms

certaindoubtlesspositivesure

Example

More examples

"Unsure of which suitor she wanted to marry, the princess vacillated, saying now one, now the other."

Etymology

From Middle English unsure, equivalent to un- + sure. Piecewise doublet of insecure and unsecure.

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.