Something that lies next to something else, especially the side of a right triangle that is neither the hypotenuse nor the opposite.
"In solving trigonometry problems involving a right triangle, students must identify which leg is adjacent to the given angle rather than using the one opposite it."
In plain English: An adjacent noun is something that sits right next to another thing without any space between them.
"The adjacent room was filled with laughter and music from the party next door."
nearest in space or position; immediately adjoining without intervening space
"had adjacent rooms"
"in the next room"
"the person sitting next to me"
"our rooms were side by side"
having a common boundary or edge; abutting; touching
"Rhode Island has two bordering states; Massachusetts and Connecticut"
"the side of Germany conterminous with France"
"Utah and the contiguous state of Idaho"
"neighboring cities"
near or close to but not necessarily touching
"lands adjacent to the mountains"
"New York and adjacent cities"
Lying next to, close, or contiguous; neighboring; bordering on.
"The two adjacent rooms shared a common wall without any doorway between them."
In plain English: Adjacent means being right next to something else with nothing between them.
"The house next door is adjacent to our garden fence."
Usage: Use "adjacent" when describing two objects that share a common boundary or lie directly beside one another without any gap in between. This term is often confused with "nearby," but while nearby items can be separated by distance, adjacent ones must touch or abut each other.
Next to; beside.
"The two adjacent rooms share a common wall."
The word adjacent comes from the Latin phrase adiacens, which literally means "lying by." It entered English to describe things that are situated next to each other.