undermost
adjectiveUK /ˈʌndəməʊst/
US /ˈʌndərˌmoʊst/
The lowest or deepest one in a group or stack.
The undermost blanket kept the cold from coming up through the floor.
RELATED WORDS
OTHER MEANINGS
2. Situated farthest down or beneath all others in position.
The undermost shelf held the heaviest books.
3. Lowest in rank, importance, or status.
He felt like the undermost member of the team.
4. The part or layer that lies beneath everything else.
The undermost layer of rock was the oldest.