食う
くう
kuu
= to eat (rough/casual, masculine) — also: to eat up (time/money), to get bitten by insects, to make a living, to get the short end of a deal, to upstage someone
Kuu means exactly the same thing as taberu (to eat) — but where taberu is neutral and safe, kuu is blunt, rough, and unmistakably masculine. It’s the word a guy grunts to his buddies before diving into a bowl of ramen, not something you’d say to your boss.
At its core, 食う (kuu) just means to eat, functioning as a rougher stand-in for taberu. Typical casual usage looks like meshi kuu? (“wanna eat?”) or mou kutta (“already ate”). But kuu has drifted far beyond the dinner table into a cluster of figurative meanings that native speakers use constantly: jikan wo kuu (to eat up time), kane wo kuu (to eat up money/be costly), ka ni kuwareru (to get bitten by a mosquito, passive form), kutte iku or simply kuu (to make a living, as in kono shigoto de kutte ikeru ka — “can I make a living doing this job?”), wari wo kuu (to get a raw deal / end up on the losing side), hito wo kutta taido (an impudent, mocking attitude — literally “an attitude that eats people”), and senpai wo kuu (to outshine or upstage a senior, as when a rookie steals the spotlight). As a godan verb it conjugates kutta (past), kuwareru (passive/potential-adjacent), and kutte (te-form).
The single biggest trap for learners is register: kuu sounds coarse and masculine, so using it with a teacher, client, or anyone you’re not close to will land as rude or try-hard. Stick to taberu in neutral settings and meshiagaru when being polite; save kuu for close friends, casual banter, or when quoting someone’s blunt speech. Second, kuu is a hub for idioms — jikan wo kuu (eats up time), ka ni kuwareru (gets bitten by mosquitoes), wari wo kuu (gets shortchanged), and kutte kakaru (to snap back aggressively at someone) all reuse the same verb in non-literal ways, so recognizing kuu in context matters even if you never say it yourself. Third, remember the godan conjugation pattern (kuwanai, kuimasu, kutta, kutte) so you don’t accidentally treat it like an ichidan verb.
Everyday use
腹減った、なんか食おうぜ。
Hara hetta, nanka kuou ze.
I’m hungry, let’s grab something to eat.
Casual / Social Media
キャンプで蚊にめっちゃ食われた…全身かゆい。
Kyanpu de ka ni meccha kuwareta… zenshin kayui.
I got absolutely eaten alive by mosquitoes camping… itchy all over.
Formal / Cultural context
この会議、思ったより時間を食いましたね。そろそろお食事の準備をなさってください。
Kono kaigi, omotta yori jikan wo kuimashita ne. Sorosoro oshokuji no junbi wo nasatte kudasai.
This meeting ate up more time than expected. Please go ahead and prepare for your meal now.
Japanese has a striking three-tier system for a single action — eating — and kuu sits at the rough end of it: meshiagaru (deeply polite, reserved for people you respect), taberu (the neutral default taught in every textbook), and kuu (blunt, masculine-coded, used among close friends or by characters meant to sound tough or working-class). Hearing which one a speaker chooses tells you instantly about their relationship to the listener, their gender presentation, and the formality of the scene — a layer of social information English’s single word “eat” simply can’t carry.
What makes kuu especially interesting linguistically is how productive it is as a base for idioms. A single physical action, eating, becomes a metaphor for time disappearing (jikan wo kuu), money draining away (kane wo kuu), insects biting (ka ni kuwareru), someone scraping by financially (kutte iku), and even someone stealing the spotlight from a superior (senpai wo kuu). This kind of metaphorical spread from a common verb is typical of how Japanese builds abstract expressions out of everyday physical vocabulary, and it’s exactly why kuu shows up constantly in casual conversation despite its rough edge.