[rabboRubble]

Off the top of my head, the only place I can recall the 喫 character appearing is in the word 喫茶店 (coffee / tea shop). To eat Japanese would use the 食べる or　召し上がる. After referring to a dictionary, there is a word 喫する，but it's not common (as in I don't recall ever hearing or learning this word) and means more generally consume by mouth as in drink / eat / smoke. Yes, the Chinese 喫 means eat, but no the meaning is not exactly the same and not used with the frequency of the word eat 食べる or　召し上がる.

[yorwba]

Conversely, 食 also means "eat" in Chinese, but is now used almost exclusively in nouns like 食物 (food) or 食堂 (dining hall). The Chinese character inventory is simply too large to keep all possible uses, especially across different languages.

[spacehunt]

食 is still being used everyday in Cantonese as a verb. Granted there are some who classifies Cantonese as a different language from Mandarin, as there are many differences between the two such as this example.

[rabboRubble]

Yep!

[jasonjei]

Right—I was only writing about the character form. 食べる is used to mean to eat, but as far as raw characters are concerned, Japanese doesn’t use 吃 but rather 喫, the non-simplified form.

[rabboRubble]

Apparently there is a use for 吃 in Japanese, 吃 is a sound used to represent a tile being discarded in a game, in compounds such as 吃驚, to be surprised. I think this compound is also used in Mandarin with the same meaning. Quick check of my Chinese dictionary indicates yes, they are a shared character compound / meaning.

Edit: fixing up my Japanese

[amake]

Japanese does use it, but it's rare: 吃（ども）る to stutter