好機|こうきkouki[1]atamadaka (head-high)

1. noungood opportunity; chance
   この好機こうきを逃のがすな。↗

   Don't let this chance slip by.

• Synonym機会きかいNeutralThe most general, neutral word for a chance or opportunity. 「好機」 stresses that the opportunity is favorable and leans written/formal.
• SynonymチャンスCasualA colloquial loanword for a chance, as in 「チャンスを逃す」. 「好機」 is more written/formal.
• Synonym時宜じぎWrittenWritten/formal prose: what the occasion calls for, as in 「時宜を得た発言」. 「好機」 centers on the opportunity itself.
• Synonym時機じきNeutralThe timing or right moment, as in 「時機を待つ」. 「好機」 adds that the moment is a favorable one.
• Related潮時しおどきWrittenWritten/formal prose: the right moment to do or quit something, as in 「今が潮時だ」. 「好機」 focuses on a favorable opportunity.
• Related幸運こううんNeutralGood luck or fortune — a related concept only. 「好機」 is a time to act; 「幸運」 is luck itself.
• Related時節じせつWrittenWritten/formal prose: a season or the state of the times, as in 「時節柄」. 「好機」 centers on a favorable chance.
• Related潮合しおあいWrittenWritten/formal prose and rare: the tide's turn, or figuratively a suitable time. Everyday speech uses 「潮時」 instead.

Use 「好機」 for a favorable opportunity, as in 「好機到来」 or 「好機を逃す」. For an ordinary chance pick 「機会」 or the colloquial 「チャンス」; for the moment to quit or change course, 「潮時」; for what suits the occasion, 「時宜」.

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

1. 物事ものごとをするのに良よい機会きかい。