切っ掛け
きっかけ · kikkake · JLPT N2 · noun
opportunity
🚪 切 (cut) + 掛 (hang on): a cut that gives you a hook to start from
Sounds like kick-a-kay: a kick gets things moving. A chance, a cue, or an excuse all give you a hook to begin from.
切 — 七 (phonetic) + 刀 (knife radical)
切 is a semantic-phonetic compound: 刀 'knife' gives the meaning of cutting, while 七 supplies the sound. The original sense was to slice or cut with a blade. From there it extended figuratively to 'close to' (as in pressed against) and 'urgent/earnest', as in 切实.