It's confusing, I know. In grammar, an adjunct is defined as a clause or phrase that's
added to a sentence that, while not essential to the sentence's structure, amplifies its meaning, such as for several hours in We waited for several hours. adjunct - Definitions from Dictionary.com
Broadly defined, thought, even in linguistics, an
adjunct is something added to another thing but not essential to it. Think of it as, added junk

, an optional constituent of a construction:
Ex: A
pretty dress <
adjunct +
headword>
All the best.
