Antonyms of adj overconfident

1 sense of overconfident

Sense 1
cocksure, overconfident, positive -- (marked by excessive confidence; "an arrogant and cocksure materialist"; "so overconfident and impudent as to speak to the queen"; "the less he knows the more positive he gets")

INDIRECT (VIA confident) -> diffident, shy, timid, unsure -- (lacking self-confidence; "stood in the doorway diffident and abashed"; "problems that call for bold not timid responses"; "a very unsure young man")

Similarity of adj overconfident

1 sense of overconfident

Sense 1
cocksure, overconfident, positive -- (marked by excessive confidence; "an arrogant and cocksure materialist"; "so overconfident and impudent as to speak to the queen"; "the less he knows the more positive he gets")
       => confident (vs. diffident) -- (having or marked by confidence or assurance; "a confident speaker"; "a confident reply"; "his manner is more confident these days"; "confident of fulfillment")