すっぱい
すっぱい · suppai · JLPT N3 · i-adj
sour
🍋 su = 酢, vinegar + -ppai, full of: vinegary, so sour
Written 酸っぱい, from the old adjective 酸い (sui, sour). The -っぱい ending also shows up in しょっぱい (salty). Sound hook: suppai sounds like super pie, and a lemon super pie is very sour.