A moment during legal or judicial proceedings when evidence or other information, usually unknown to most present, is introduced into the record in a manner seen as determinative of the outcome of the proceedings regardless of whatever else occurs.

A mountainous region of New South Wales, Australia. / A small mountain range on Ellesmere Island, Nunavut, Canada.

plural of mountain unit

A person (especially an entomologist) or animal that catches moths.

An aphthous ulcer; an open sore in the mouth, or rarely a break in the mucous membrane or the epithelium on the lips or surrounding the mouth.

(Internet) The set of CSS rules that govern the size, shape, spacing, borders, and margins of web page elements.

A difficult challenge.

(idiomatic) The moment or instant at which the solution to a problem, or some other significant realization, becomes clear.

Alternative form of aha moment

Alternative form of birdsmouth.