Meaning of UPPER in English
1》 situated above another participle
↘higher in position or status.
↘(often Upper ) Geology & Archaeology denoting a younger (and hence typically shallower) part of a stratigraphic or archaeological division: the Upper Palaeolithic.
2》 situated on higher ground.
3》 [in place names ] situated to the north.
■ noun the part of a boot or shoe above the sole.
have (or gain ) the ~ hand have (or gain) an advantage or control.
on one's ~s informal extremely short of money.
the ~ crust informal the ~ classes.
ME: from the adjective up + -er 2 .
■ noun informal a stimulating drug, especially an amphetamine.
1960s: from the verb up + -er 1 .
Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004