1.  calendar(n = noun.time) - a system of timekeeping that defines the beginning and length and divisions of the year;
Derived form adjective calendric₁

2.  calendar(n = noun.communication) - a list or register of events (appointments or social events or court cases etc); "I have you on my calendar for next Monday"
Derived form verb calendar₁

3.  calendar(n = noun.group) - a tabular array of the days (usually for one year);
Derived form verb calendar₁, adjective calendric₁

   calendar(v = verb.cognition) - enter into a calendar;
Derived form noun calendar₂, noun calendar₃
Sample sentences: Somebody ----s somebody; Somebody ----s something

1.  An orderly arrangement of the division of time, adapted to the purposes of civil life, as years, months, weeks, and days; also, a register of the year with its divisions; an almanac. [1913 Webster]

2.  A tabular statement of the dates of feasts, offices, saints' days, etc., esp. of those which are liable to change yearly according to the varying date of Easter. [1913 Webster]

3.  An orderly list or enumeration of persons, things, or events; a schedule; as, a calendar of state papers; a calendar of bills presented in a legislative assembly; a calendar of causes arranged for trial in court; a calendar of a college or an academy. [1913 Webster]

   To enter or write in a calendar; to register. Waterhouse. [1913 Webster]

calendar, n. & v.
--n.
1 a system by which the beginning, length, and subdivisions of the year are fixed.
2 a chart or series of pages showing the days, weeks, and months of a particular year, or giving special seasonal information.
3 a timetable or programme of appointments, special events, etc.
--v.tr. register or enter in a calendar or timetable etc.

Idiom:
calendar month (or year) see MONTH, YEAR.

Derivative:
calendric adj. calendrical adj.

Etymology:
ME f. AF calender, OF calendier f. L calendarium account-book (as CALENDS)

N  chronometry, horometry, horology, date, epoch, style, era, almanac, calendar, ephemeris, register, registry, chronicle, annals, journal, diary, chronogram, clock, wall clock, pendulum clock, grandfather's clock, cuckoo clock, alarm clock, clock radio, watch, wristwatch, pocket watch, stopwatch, Swiss watch, atomic clock, digital clock, analog clock, quartz watch, water clock, chronometer, chronoscope, chronograph, repeater, timekeeper, timepiece, dial, sundial, gnomon, horologe, pendulum, hourglass, clepsydra, ghurry, chronographer, chronologer, chronologist, timekeeper, annalist, calendar year, leap year, Julian calendar, Gregorian calendar, Chinese calendar, Jewish calendar, perpetual calendar, Farmer's almanac, fiscal year, chronological, chronometrical, chronogrammatical, cinquecento, quattrocento, trecento, o'clock.

N  record, trace, vestige, relic, remains, scar, cicatrix, footstep, footmark, footprint, pug, track mark, wake, trail, scent, piste, monument, hatchment, slab, tablet, trophy, achievement, obelisk, pillar, column, monolith, memorial, memento, testimonial, medal, commemoration, record, note, minute, register, registry, roll, cartulary, diptych, Domesday book, catalogue raisonne, entry, memorandum, indorsement, inscription, copy, duplicate, docket, notch, muniment, deed, document, deposition, proces verbal, affidavit, certificate, notebook, memorandum book, memo book, pocketbook, commonplace book, portfolio, pigeonholes, excerpta, adversaria, jottings, dottings, gazette, gazetteer, newspaper, daily, magazine, almanac, almanack, calendar, ephemeris, diary, log, journal, daybook, ledger, cashbook, petty cashbook, professional journal, scientific literature, the literature, primary literature, secondary literature, article, review article, archive, scroll, state paper, return, blue book, statistics, compte rendu, Acts of, Transactions of, Proceedings of, Hansard's Debates, chronicle, annals, legend, history, biography, Congressional Records, registration, registry, enrollment, inrollment, tabulation, entry, booking, signature, recorder, journalism, recording, tape recording, videotape, compact disk, floppy disk, diskette, hard disk, Winchester disk, read-only memory, ROM, write once read mostly memory, WORM, on record, exegi monumentum aere perennium, read their history in a nation's eyes, records that defy the tooth of time.

VB  record, put on record, place on record, chronicle, calendar, hand down to posterity, keep up the memory, commemorate, report, write, commit to writing, reduce to writing, put in writing, set down in writing, writing in black and white, put down, jot down, take down, write down, note down, set down, note, minute, put on paper, take note, make a note, take minute, take memorandum, make a return, mark, sign, enter, book, post, post up, insert, make an entry of, mark off, tick off, register, enroll, inscroll, file, burn into memory, carve in stone.