idiom · referring to speaking without evidence or basis

他总是空口许诺，从不付诸行动。

noun · eating meat or vegetable dishes without accompanying rice, wine, or other staple food

这道菜口味很重，不适合空口吃。

adverb · eating rice or other staple food without any meat or vegetable dishes

他今天没胃口，就空口吃了一碗白饭。