Meaning of “upper” - Learner’s Dictionary

upper

adjective [ always before noun ] uk us /ˈʌpər/
POSITION

B1 at a higher position:

an upper floor
the upper lip
the upper body
SOCIAL CLASS
the upper limit

the highest amount or level, or the longest time that something is allowed

→ See also get/gain the upper hand

(Definition of “upper” from the Cambridge Learner’s Dictionary © Cambridge University Press)