To Eat
To Consume
godan verb, transitive verb
You know the kanji means eat, and you also already know 食べる. So what's the deal with this also meaning to eat?
食う carries a more masculine and coarse tone than 食べる, so it can come off as rough or impolite in certain situations. It also has a wider set of usages, for example in saying that something is eating up time or resources, or saying that you were bitten by a bug. You'll come across more of these, but they're all pretty straightforward, so don't worry!
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You do know that reading, but this uses a different one, so here's a mnemonic to help you:
There's nothing you love to eat more than cookies (く). You could eat them day and night, but watch out, as that might get a little… time-consuming.
飯を食う
to eat a meal
時間を食う
to consume time, to take up time
割を食う
to get the short end of the stick, to bear the brunt
金を食う
to eat up money
虫に食われる
to be bitten by a bug, to be eaten by a bug
昼飯を食う時間がなかったんだ。
I didn't have time to eat lunch.
げ、シルクのスーツが虫に食われてる！
Oh no, my silk suit is being eaten by bugs!
時間ばっかり食って、割りに合わない仕事だったよ。
It was a job that just ate up my time and didn't pay off.