EXPLANATORY
explanatory
(adjective) serving or intended to explain or make clear; “explanatory notes”; “an explanatory paragraph”
Source: WordNet® 3.1
Etymology
Adjective
explanatory (comparative more explanatory, superlative most explanatory)
Intended to serve as an explanation.
(of a person) Disposed to explain.
Source: Wiktionary
Ex*plan"a*to*ry, a. Etym: [L. explanatorius.]
Definition: Serving to explain; containing explanation; as explanatory
notes. Swift.
Source: Webster’s Unabridged Dictionary 1913 Edition