Origin and history of stage

mid-13c., "horizontal division of a structure, floor or story of a building;" early 14c., "raised platform used for public display" (also of the platform beneath the gallows), from Old French estage "building, dwelling place; stage for performance; phase, stage, rest in a journey" (12c., Modern French étage, only in the sense "story of a house, stage, floor, loft"), from Vulgar Latin *staticum "a place for standing," from Latin statum, past participle of stare "to stand" (from PIE root *sta- "to stand, make or be firm").

The etymological notion is "standing place, something to stand on," hence "place where anything is publicly exhibited." The meaning "platform for speakers, performers, or presentation of a play" is attested from late 14c.; the stage as a general term for "profession of an actor, dramatic composition or acting" is from 1580s.

The sense of "period of development or time in life" is recorded by early 14c., probably from the Middle English sense of "degree or step on the 'ladder' of virtue, the 'wheel' of fortune, etc.," in parable illustrations and morality plays. The meaning "level of water in a river, etc." is from 1814, American English.

The meaning "single step in a sequence or gradual process, stage of a journey" is by late 14c. Hence "roadside stopping place, place of rest on a journey or where horses are changed" (c. 1600), the sense in stagecoach. 

Stage-name is from 1727. Stage-mother (n.) in the overbearing mother-of-an-actress sense is from 1915. Stage-box "proscenium box" is by 1739. Stage-door, giving access to a stage, is from 1761; hence Stage-Door Johnny "young man who frequents stage doors seeking the company of actresses, chorus girls, etc." (1907). Stage whisper, a loud one, as used by an actor on stage to be heard by the audience, is attested by 1865. Stage-direction is attested by 1790.

mid-14c., stagen, "to erect, construct," from stage (n.). The meaning "put into or represent (a person) in a play or on stage" is from c. 1600; that of "put (a play) on the stage" is by 1879; the general sense of "to mount" (a comeback, an attack, etc.) is attested from 1924. Related: Staged; staging.