noun
Colloquial noun for an empty stomach, often used when feeling hungry or when eating/drinking on an empty stomach.
See also: 空き腹
すきっ腹で酒を飲むと酔いが回りやすい。
If you drink alcohol on an empty stomach, you get drunk easily.
すきっ腹を
I came home with an empty stomach.
空腹 is the standard, neutral term for an empty stomach. すきっ腹 is more colloquial and often carries a slightly rougher or more vivid nuance.
From 空き (すき, 'empty') + 腹 (はら, 'belly'), with a geminate consonant insertion (促音便) for colloquial emphasis. The exact historical derivation is uncertain, but the form is a common colloquial variant of 空き腹 (すきはら).