never defeated; always victorious

immature and not fully developed / having a low level of economic productivity and technological sophistication / (photography) of a film that has had insufficient development before being fixed

simple past tense and past participle of underdevelop

A cut made in the lower part of something; the material so removed. / The notch cut in a tree to direct its fall when being felled. / The underside of a sirloin of beef; the fillet.

To sell (something) at a lower price, or to work for lower wages, than a competitor. / To create an overhang by cutting away material from underneath. / To undermine. / To strike a heavy blow upward.

Produced by undercutting. / Designed so as to cut from the underside. / Having the parts in relief cut under.

A student at a university who has not yet received a degree.

Of, relating to, or being an undergraduate.

Irrefutable, or impossible to deny.

secret; clandestine / (by extension) dishonest and sneaky; done in a secret or sly manner / (in various ball games, of a ball) thrown (etc.) with the hand brought forward and up from below