uppermost

adjective Also upmost.

1. highest in place, order, rank, power, etc.: the uppermost peaks of the mountain; the uppermost class of society.
2. topmost; predominant: a subject of uppermost concern.

adverb

3. in or into the uppermost place, rank, or predominance: The blossoms grow uppermost on the stems of these flowers; the thoughts that came uppermost to her mind.

adjective Also: upmost

1. highest in position, power, importance, etc

adverb

2. in or into the highest position, etc

late 15c., from upper + -most.