C
anniversary
annual
annual holiday
biannual
bicentenary
bicentennial
biennial
bimonthly
birthday
bissextile day
biweekly
catamenial
cental
centare
centenarian
centenary
centennium
centesimal
centigrado
centigram
centimeter
centipede
centistere
centred
centref
centrev
centumvir
centumvirate
centuple
centuplicate
centurial
centurion
century
commemoration
cwt
daily
decennial
diamond jubilee
diurnal
fortnightly
golden wedding anniversary
gross
hebdomadal
hecatomb
holy days
hourly
hundred
hundredfold
day of remembrance
100th
141st
50th
70th
fiftieth
forty-third
jubilee
seventieth
sixtieth
tercentenary
thirtieth
millennial
perennial
quadrennial
triennial