Definition of "Upper" :
noun: a central nervous system stimulant that increases energy and decreases appetite; used to treat narcolepsy and some forms of depression
noun: piece of leather or synthetic material that forms the part of a shoe or boot above the sole that encases the foot
"Uppers come in many styles."
noun: the higher of two berths
adjective: higher in place or position
"The upper bunk."
adjective: superior in rank or accomplishment
"The upper half of the class."
adjective: the topmost one of two