en.wiktionary.orgthiên niên kỉ - Wiktionary, the free dictionary From Wiktionary, the free dictionary thiên niên kỷ Sino-Vietnamese word from 千年紀, composed of 千年 (“1000 years; millennium”) and 紀 (“period”). (Hà Nội) IPA(key): [tʰiən˧˧ niən˧˧ ki˧˩] (Huế) IPA(key): [tʰiəŋ˧˧ niəŋ˧˧ kɪj˧˨] (Saigon) IPA(key): [tʰiəŋ˧˧ niəŋ˧˧ kɪj˨˩˦] thiên niên kỉ a millennium (one thousand years)