1A trigger, opportunity, or motive that starts something happening — the occasion or cue that prompts an action. Very common in everyday speech.
留学が英語を好きになったきっかけだ。
Studying abroad was what got me to like English.
友達に誘われたのがジョギングを始めるきっかけだった。
Being invited by a friend was what got me started jogging.
健康診断での指摘が禁煙のきっかけになった。
A note on my health checkup was the impetus to quit smoking.
何かいい話のきっかけがあれば、声をかけてみて。
If you get a good opening to talk, go ahead and speak up.