unorthodox, a. heterodox.

unpacifiable, a. [implacable], [unappeasable], [unreconcilable].

unpaid, a. outstanding, [payable], [due], unliquidated.

unpardonable, a. inexpiable, [unatonable], irremissible, [unforgivable].

unpassable, a. [impassable].

unpenetrable, a. [impenetrable], [impervious], imperforable.

unpierceable, a. imperforable, [impenetrable].

unplanted, a. [fallow].

unpleasant, a. [disagreeable], [uncongenial].

unplowed, a. [fallow].