WordNet

a unit of geological time during which a system of rocks formed; "ganoid fishes swarmed during the earlier geological periods" (同)geological period
(ice hockey) one of three divisions into which play is divided in hockey games
the end or completion of something; "death put a period to his endeavors"; "a change soon put a period to my tranquility"
the interval taken to complete one cycle of a regularly repeating phenomenon
a punctuation mark (.) placed at the end of a declarative sentence to indicate a full stop or after abbreviations; "in England they call a period a stop" (同)point, full_stop, stop, full point

PrepTutorEJDIC

(あることが続く)『期間』 / (歴史的な)『時代』 / (試合の)『一区切り』,ピリオド / 授業時間,時限: / (循環して起こる現象などの)周期 / (回転運動などの)周期 / 紀(地質時代の区分の一つ;era(代)の下,epoch(世)の上) / 《おもに米》『ピリオド』,終止符(《英》full stop;Mr.,U.S.など略語の符号(.)も含む) / 《複数形で》《文》掉尾(とうび)文(多くの節から成り,論理的に緊密な構成をもっている文) / 《名詞の前にのみ用いて》ある時代[特有]の,時代物の / (文の終わりに感嘆詞的に)以上,終わり・月経（期間）