1.  calendar(n = noun.time) - a system of timekeeping that defines the beginning and length and divisions of the year;
is a kind of arrangement, organisation, organization, system
has parts: embolism, intercalation
has particulars: lunar calendar, lunisolar calendar, solar calendar
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"
is a kind of list, listing
has particulars: docket
Derived form verb calendar₁

3.  calendar(n = noun.group) - a tabular array of the days (usually for one year);
is a kind of table, tabular array
has particulars: perpetual calendar
Derived forms verb calendar₁, adjective calendric₁

   calendar(v = verb.cognition) - enter into a calendar;
is one way to schedule
Derived forms noun calendar₂, noun calendar₃
Sample sentences: Somebody ----s something; Somebody ----s somebody

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]
"Shepherds of people had need know the calendars of tempests of state." Bacon. [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.

appointment calendar, calendar day, calendar method, calendar method of birth control, calendar month, calendar week, calendar year, church calendar, ecclesiastical calendar, farmer's calendar, greek calendar, gregorian calendar, gregorian calendar month, hebrew calendar, hindoo calendar, hindu calendar, hindu calendar month, islamic calendar, islamic calendar month, jewish calendar, jewish calendar month, julian calendar, lunar calendar, lunisolar calendar, mohammedan calendar, moslem calendar, muhammadan calendar, muslim calendar, new style calendar, old style calendar, perpetual calendar, revolutionary calendar, revolutionary calendar month, roman calendar, solar calendar