phase: [19] Greek phásis (a derivative of the verb phaínein ‘show’, source of English phantom) meant ‘appearance’, and also ‘cyclical apparent form of a planet, moon, etc’. This was adopted into modern Latin as phasis, and it originally passed into English (in the 17th century) in the Latin plural form phases. Phase represents a new singular formed from this. The more familiar modern sense ‘stage in a sequence’ is a metaphorical extension of the astronomical meaning. => phantom
phase (n.)
1705, "phase of the moon," back-formed as a singular from Modern Latin phases, plural of phasis, from Greek phasis "appearance" (of a star), "phase" (of the moon), from stem of phainein "to show, to make appear" (see phantasm). Latin singular phasis was used in English from 1660. Non-lunar application is first attested 1841. Meaning "temporary difficult period" (especially of adolescents) is attested from 1913.
phase (v.)
"to synchronize," 1895, from phase (n.). Meaning "to carry out gradually" is from 1949, hence phase in "introduce gradually" (1954), phase out (1954). Related: Phased; phasing.
例文
1. The phase of writing that is actually most important is revision.
実際に書く上で最も重要な段階は修正です。
2.The crisis is entering a crucial，critical phase .
現在、危機は決定的な重要な段階に入っている。
3.The carrier wave has got out of phase with the signal wave.
搬送波同信号波は異相である。
4.In 2006 work began upon the second phase of the project.
2006年第2期工事が着工した。
5.The first phase of the project has been completed.