"the period of menstruation," 1680s, from past-participle stem of Late Latin menstruare, from menstruus "monthly" (from mensis "month;" see moon (n.)) + -ation. Old English equivalent was monaðblot "month-blood." Middle English had menstrue (n.), late 14c., from Old French menstrue, from Latin menstruum.
1680s, "pollute with menstrual blood" (transitive), a sense now rare or obsolete; 1752 as "to discharge the menses," probably a back-formation from menstruation, or else from Latin menstruatus, past participle of menstruare, from menstruus "monthly," from mensis "month" (see moon (n.)). Related: Menstruated; menstruating.
"having the monthly flow or discharge," early 15c., from Old French menstrueus and directly from Medieval Latin *menstruosus, from Latin menstruum "of or belonging to menstruation," from menstruus (adj.) "that happens every month, monthly," from mensis "month" (see moon (n.)).
early 15c., periode, "a course or extent of time; a cycle of recurrence of a disease," from Old French periode (14c.) and directly from Medieval Latin periodus "recurring portion, cycle," from Latin periodus "a complete sentence," also "cycle of the Greek games," from Greek periodos "cycle, circuit, period of time," literally "a going around," from peri "around" (see peri-) + hodos "a going, traveling, journey; a way, path, road," a word of uncertain origin (see Exodus).
Sense of "repeated cycle of events" led to that of "interval of time." From 1712 as "an indefinite part of any continued state or series of events;" by 1727 as "time in which a circuit or revolution (as of a heavenly body) is made." Sense of "episode of menstruation" is by 1829, probably short for period of menstruation (1808), etc.
The meaning "dot marking end of a sentence" is recorded c. 1600, from the earlier sense of "a complete sentence, from one full stop to another," then "a full pause at the end of a sentence" (1580s). The educational sense of "portion of time set apart for a lesson" is from 1876. The sporting sense "division of a game or contest" is attested by 1898. As an adjective from 1905; period piece is attested from 1911.
Old English læt "occurring after the customary or expected time," originally "slow, sluggish, slack, lax, negligent," from Proto-Germanic *lata- (source also of Old Norse latr "sluggish, lazy," Middle Dutch, Old Saxon lat, Dutch laat, German laß "idle, weary," Gothic lats "weary, sluggish, lazy," latjan "to hinder"), from PIE *led- "slow, weary," from root *lē- "to let go, slacken."
From mid-13c. as "occurring in the latter part of a period of time." From c. 1400 as "being or occurring in the near, or not too distant, past; recent" (of late). From this comes the early 15c. sense "recently dead, not many years dead" (as in the late Mrs. Smith). Of menstruation, attested colloquially from 1962. Expression better late than never is attested from late 15c. As an adverb, from Old English late "slowly."
c. 1200, "act or fact of changing," from Anglo-French chaunge, Old French change "exchange, recompense, reciprocation," from changier "to alter; exchange; to switch" (see change (v.)). Related: changes.
Meaning "a different situation, variety, novelty" is from 1680s (as in for a change, 1690s). Meaning "something substituted for something else" is from 1590s. Meaning "place where merchants meet to do business" is from c. 1400. Meaning "the passing from life to death" is biblical (161os).
The financial sense of "balance of money returned after deducting the price of a purchase from the sum paid" is first recorded 1620s; hence to make change (by 1865). Bell-ringing sense is from 1610s, "any sequence other than the diatonic." Hence the figurative phrase ring changes "repeat in every possible order" (1610s). Figurative phrase change of heart is from 1828. In reference to women, change of life "final cessation of menstruation" is recorded from 1834.