I was confused by the lyrics of the children's song 三个和尚:
I've seen other versions of the song that use 喝 instead of 吃, which makes more sense to me. Can 吃 be used to mean "drink" as well as "eat"?
From my point of view, 吃 here is a correct but uncommon usage. See the first explaination here .
Well you can 吃酒，or 吃喜酒 at a wedding, but that involves eating and drinking.
zdic has: (4) 饮;喝 [drink]。如:吃血(饮血酒);吃茶(喝茶)
A song about human nature.
一个和尚挑水吃 When you're alone you have to help yourself.
两个和尚抬水吃 2 people can cooperate
三个和尚没水吃呀 when there are 3 people, each thinks, 'Why should I do it? Let them do it.'
Edit: thinking about oil, which is a liquid，I was just reading an article about 副食品:
According to 《汉英简明词典》
吃 actually can mean "drink"
In addition, 吃水 here dose not merely mean drink water, it can further extend to use water for daily life, such as washing.
Similar expression, 吃水不忘挖井人
Sure. You can eat liquid, if you understand the notion of "eating" (吃) in a more general sense as "consuming by way of admission into the mouth" as opposed to "chewing". For example, another use of this in this way is that the act of taking medicines orally is called "吃药" - to "eat medicine" (to take by injection is not called this, but rather "打针" - to "hit needle", and the term [verb] for the act of injecting a substance with a needle is "注射" [not really sensible individually as they're two characters with generic meanings surrounding this process]), even though one typically does not chew most pill medicines unless they are made for it. It's a wider cognition/conceptualization than with which English speakers conventionally understand by "eating", which should be expected since this is Mandarin, not English.
But as said in the other posts, it's not common to use with liquid, 喝 is typically used instead ("drink", to consume specifically liquid with no chewing).
I think it all depends on which Chinese you learned. In Chinese "吃" can be used for liquids, but in traditional we don't use "吃" for liquids, we use "喝" instead.