upstairs

(noun) the part of a building above the ground floor. Example: "No one was allowed to see the upstairs."

(adj) on or of upper floors of a building. Synonyms: upstairs (vs. downstairs), upstair. Examples: "The upstairs maid." "An upstairs room."

(adv) on a floor above. Synonyms: up the stairs, on a higher floor. Example: "They lived upstairs."

(adv) with respect to the mind. Example: "She's a bit weak upstairs."