Entries linking to derivational
early 15c., derivacioun, originally in a now-obsolete sense in medicine, "a drawing off or away, a turning aside," from Old French dérivation (14c.) and directly from Latin derivationem (nominative derivatio) "a leading off, turning away," also "derivation of a word, etymology," noun of action from past-participle stem of derivare "to lead or draw off" (see derive).
Grammatical sense, "drawing or tracing of a word in its development or formation from its more original root or stem, a statement of the origin or history of a word" in English is from mid-15c. The general meaning "origination, descent" is from c. 1600; that of "act or fact of drawing or receiving from a source" is from 1650s.
the morphological relation between `sing' and `singer' and `song' is derivational