An allusion is a literary device that refers to something (a great book or character) in an indirect way, that is, an apparent reference is made not in an explicit way.

Allegory is a literary device which expresses a bigger idea through a simple surface story. The meaning of an allegorical story is hidden under the symbols and tools used as mouthpieces.

An adage is a crisp, sharp saying which has its foundation in human life and has stood true for a very long time.

Ad hominem is an argumentation error. Ad hominem fallacy happens when a counterattack is made but on the original line of argument.

Accumulation is a literary device that puts together scattered points of similar words to generate a common and deeper feeling in writing. It is a stylistic device used by writers to produce the effect of amplification.