UNSURE

uncertain, unsure, incertain

(adjective) lacking or indicating lack of confidence or assurance; “uncertain of his convictions”; “unsure of himself and his future”; “moving with uncertain (or unsure) steps”; “an uncertain smile”; “touched the ornaments with uncertain fingers”

diffident, shy, timid, unsure

(adjective) lacking self-confidence; “stood in the doorway diffident and abashed”; “problems that call for bold not timid responses”; “a very unsure young man”

Source: WordNet® 3.1

Etymology

Adjective

unsure (comparative unsurer, superlative unsurest)

uncertain

unstable or precarious

Synonyms

• agnostic (unsure of facts, having no decided opinion on a matter)

Source: Wiktionary