Description is any type of communication that aims to make vivid a place, object, person, group, or other physical entity.
[2] Fiction writing specifically has modes such as action, exposition, description, dialogue, summary, and transition.
[3] Author Peter Selgin refers to methods, including action, dialogue, thoughts, summary, scenes, and description.
As stated in Writing from A to Z, edited by Kirk Polking, it is more than the amassing of details; it is bringing something to life by carefully choosing and arranging words and phrases to produce the desired effect.
[5] A purple patch is an over-written passage in which the writer has strained too hard to achieve an impressive effect, by elaborate figures or other means.