The 100th anniversary (or the celebration of it).

synonym: centennial.

Roget 98: five, cinque [Fr.], quint, quincux^†; six, half-a-dozen, half dozen; seven; eight; nine, three times three; dicker; ten, decade; eleven; twelve, dozen; thirteen; long dozen, baker's dozen; quintuplet; twenty, score; twenty-four, four and twenty, two dozen; twenty-five, five and twenty, quarter of a hundred; forty, two score; fifty, half a hundred; sixty, three score; seventy, three score and ten; eighty, four score; ninety, fourscore and ten; sestiad^†.    hundred, centenary, hecatomb, century; hundredweight, cwt.   ; one hundred and forty-four, gross.    thousand, chiliad; millennium, thousand years, grand [Coll.]; myriad; ten thousand, ban [Jap.], man [Jap.]; ten thousand years, banzai [Jap.]; lac, one hundred thousand, plum; million; thousand million, milliard, billion, trillion etc. ... show more

Roget 138: periodicity, intermittence; beat; oscillation etc. 314; pulse, pulsation; rhythm; alternation, alternateness, alternativeness, alternity^†.    bout, round, revolution, rotation, turn, say.    anniversary, jubilee, centenary.    catamenia^†, courses, menses, menstrual flux.    [Regularity of return] rota, cycle, period, stated time, routine; days of the week; Sunday, Monday &c.; months of the year; January &c.; feast, fast &c.; Christmas, Easter, New Year's day &c.; Allhallows^†, Allhallowmas^†, All Saints' Day; All Souls', All Souls' Day; Ash Wednesday, bicentennial, birthday, bissextile^†, Candlemas^†, Dewali, groundhog day [U.S.], Halloween, Hallowmas^†, Lady day, leap year, Midsummer day, Muharram, woodchuck day [U.S.], St.    Swithin's day, natal day; yearbook; yuletide.    punctuality, regularity, steadiness.    ... show more

Dutch: eeuwfeest
Polish: stulecie

Of or relating to or completing a period of 100 years.

synonym: centennial.

Roget 98: five, quinary^†, quintuple; fifth; senary^†, sextuple; sixth; seventh; septuple; octuple; eighth; ninefold, ninth; tenfold, decimal, denary^†, decuple^†, tenth; eleventh; duodenary^†, duodenal; twelfth; in one's 'teens, thirteenth.    vicesimal^†, vigesimal; twentieth; twenty-fourth etc. n.; vicenary^†, vicennial^†.    centuple^†, centuplicate^†, centennial, centenary, centurial^†; secular, hundredth; thousandth, etc. ... show more

Dutch: honderdjarig