Noun

• S: (n) millennium, millenary (the 1000th anniversary (or the celebration of it))
• direct hypernym / inherited hypernym / sister term
• S: (n) anniversary, day of remembrance (the date on which an event occurred in some previous year (or the celebration of it))
• S: (n) day (a day assigned to a particular purpose or observance) "Mother's Day"
• S: (n) calendar day, civil day (a day reckoned from midnight to midnight)
• S: (n) time period, period of time, period (an amount of time) "a time period of 30 years"; "hastened the period of time of his recovery"; "Picasso's blue period"
• S: (n) fundamental quantity, fundamental measure (one of the four quantities that are the basis of systems of measurement)
• S: (n) measure, quantity, amount (how much there is or how many there are of something that you can quantify)
• S: (n) abstraction, abstract entity (a general concept formed by extracting common features from specific examples)
• S: (n) entity (that which is perceived or known or inferred to have its own distinct existence (living or nonliving))
• derivationally related form
• S: (n) millennium, millenary (a span of 1000 years)
• part meronym
• S: (n) century (a period of 100 years)
• direct hypernym / inherited hypernym / sister term
• S: (n) time period, period of time, period (an amount of time) "a time period of 30 years"; "hastened the period of time of his recovery"; "Picasso's blue period"
• derivationally related form
• S: (n) millenary (a sum or aggregate of one thousand (especially one thousand years))
• direct hypernym / inherited hypernym / sister term

Adjective

• S: (adj) millenary (of or relating to the doctrine of the millennium)
• S: (adj) millenary (relating to or consisting of 1000)