Takeout is food you buy from a restaurant and carry away to eat somewhere else, usually at home. It is the American word. In Britain and Australia people say takeaway, and in Taiwan you will hear both from teachers, so it is worth holding on to the pair. It works three ways. As a noun for the food itself: 'We ordered takeout.' As a noun for a whole meal or habit: 'Friday is takeout night.' As an adjective before another noun: takeout coffee, a takeout box, a takeout menu. Two spellings are both fine — takeout as one word, or take-out with a hyphen — and one word is more common now. In a restaurant, the staff question is usually the verb, not this noun: 'For here or to go?' in America, 'Eat in or take away?' in Britain. Answer with 'to go' or 'take away', not with 'takeout'. And it is uncountable as food: order some takeout, not 'a takeout'. (Though in Britain 'a takeaway' — one meal, or the shop itself — is perfectly normal, which is one more small trap between the two Englishes.) It quietly means restaurant food, cooked for you. Bringing your own lunchbox from home is not takeout.