Definition of adjacent 1 a. The word adjacent means next to or adjoiningIn geometry the adjacent side of an angle in a right triangle is the one that is not the opposite from the. Jenny Eather.
Any two sides which share a common vertex are called adjacent sides.
Immediately adjoining without intervening space 2. In the case of a right triangle the hypotenuse is the longest side. Nearest in space or position. What does adjacent mean.