I. ˈəpə(r)ˌmōst also chiefly Brit -_məst adverb
Etymology: Middle English, from upper + most
1. : in or into the highest physical position
the blade turned uppermost
2. : in or into the most prominent position (as in the mind)
says whatever comes uppermost
II. adjective
1.
a. : situated in the highest physical position : farthest up
the uppermost falls of the river
b. : outermost
the uppermost skin
2.
a. : highest in rank or power
prominent in its uppermost councils — Current Biography
whatever faction happens to be uppermost — Jonathan Swift
b. : occupying the most prominent or most important position
the thoughts that were uppermost in my mind — R.B.Merriman
essays in which philosophical considerations are uppermost — J.E.Smith