c. 1600, "part or character one takes," from French rôle "part played by a person in life," literally "roll" (of paper) on which an actor's part is written, from Old French rolle (see roll (n.)). Not originally in English with direct reference to actors and the stage, but figurative of them. The meaning "any conspicuous function performed characteristically by someone" is by 1875. In the social psychology sense is from 1913. Role model, one taken by others as a model in performance of some role, is attested by 1957.
mid-15c., "action or process of building or construction;" 1610s, "that which is constructed, a building or edifice;" from Latin structura "a fitting together, adjustment; a building, mode of building;" figuratively, "arrangement, order," from structus, past participle of struere "to pile, place together, heap up; build, assemble, arrange, make by joining together," related to strues "heap," from PIE *streu-, extended form of root *stere- "to spread."
also re-cast, c. 1600, "to throw again," from re- "back, again" + cast (v.). Sense of "to cast or form anew, remodel," especially of literary works and other writing, is from 1790. Meaning "compute anew" is by 1865. Theater sense of "assign an actor or role to another role or actor" is by 1951. Related: Recasting. As a noun, "a fresh molding, arrangement, or modification," by 1840.
by 1979, initialism (acronym) from role-playing game (see roleplay). As an initialism for rocket-propelled grenade, by 1970.
1824 in biology, "science of the outer form and inner structure of animals and plants," from German Morphologie (1817); see morpho- "shape" + -logy "study of." By 1869 in philology, "science of structure or forms in language." General sense of "shape, form, external structure or arrangement" is by 1890. Related: Morphological; morphologist. Related: Morphologist.
early 15c., "network, structure," from Latin textura "web, texture, structure," from stem of texere "to weave" (from PIE root *teks- "to weave, to fabricate, to make; make wicker or wattle framework"). Meaning "structural character" is recorded from 1650s. Related: Textural.