the.com/overconfidence

means An excess of confidence in your own abilities or judgment that outstrips what the facts can actually support.

from A straightforward compound: 'over-' (too much, beyond proper limits) plus 'confidence,' from Latin 'confidentia' — 'con-' (thoroughly) and 'fidere' (to trust). The root 'fidere' is the same one behind 'fidelity' and 'faith.' So confidence is, at heart, full trust — and overconfidence is that trust running past the evidence that should be keeping it in check.