Englishfor English speakers
upper
Adjective
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The upper thing is the one that is in a higher position.
The upper floors of the building are for offices and the lower floors for housing.
upper
Noun
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A drug that stimulates a body. Uppers give a person energy and lower hunger.
He takes uppers so that he can stay awake all night studying.
boiler
Noun
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A boiler is a large container where water is heated, usually for the purpose of heating a building.
The water from the boiler heats the whole building.