期|きki[1]atamadaka (head-high)

1. noun, noun (suffix)period; time
   経済けいざいは景気後退けいきこうたい期きに入はいった。↗

   The economy has entered a recession.
2. nounopportunity; chance; occasion
3. noun, noun (suffix), geologyage
4. noun (suffix)term (e.g. in office)
5. noun (suffix)session (e.g. of parliament)
6. noun (suffix)stage (e.g. of a disease)
7. noun (suffix)season (e.g. of a TV series)

• Synonym期間きかんNeutralA stretch of time with a set start and end, as in 「契約期間」; it stands alone, while 「期」 mostly works as a suffix, as in 「第一期」「学期」.
• Synonym時期じきNeutralA particular period, season, or the right timing, as in 「時期尚早」; it stands alone, whereas 「期」 mostly serves as a suffix.
• SynonymピリオドNeutralA loanword that usually means the full stop, as in 「ピリオドを打つ」, and also a game period or an era; 「期」 mostly works as a suffix.
• SynonymタームWrittenA loanword for a school term or a set time limit, and also a technical term; found in written, specialized contexts, while 「期」 is a Sino-Japanese suffix.
• RelatedスパンNeutralA loanword for a span of time, stressing its length, as in 「長いスパンで考える」; 「期」 refers to a period or an installment.

「期」 can mean a period, an installment, or the right timing, and often works as a suffix, as in 「第二期」「思春期」. For a stretch of time use 「期間」, for a particular period 「時期」, for a time span 「スパン」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. （キ）時期じき。期間きかん。
2. （キ）機会きかい。
3. 地質ちしつ年代ねんだい区分くぶんの単位たんい。