bottommost
At the base
Bottommost means lowest or furthest down in position: the bottommost shelf, the bottommost layer of sediment.
It's the superlative form of bottom, emphasizing the absolute lowest point in a stack, series, or hierarchy.
Superlative of depth
- lowestLeast in position
- abyssImmeasurably profound depth
- nadirLowest possible point
- trenchLong narrow excavation
fathomless · chasm · seafloor · benthic · subterranean · sediment · sunken · submerge
Underlying support structure
- baseSupporting bottom structure
- footingSecure ground position
- underpinningFoundational support beneath
- substructureSupporting base beneath
groundwork · substrate · underlayer · plinth · bedrock · floor · ground-floor · basement
deepest
Superlative of depth
trench · fathomless · chasm · seafloor · benthic · subterranean · sediment · sunken · submerge · bedrock
foundation
Underlying support structure
- baseSupporting bottom structure
- footingSecure ground position
- underpinningFoundational support beneath
substructure · groundwork · substrate · underlayer · plinth · bedrock · floor · ground-floor · basement · subfloor
last
Final in sequence
tail-end · rearmost · end · hindmost · trailing · subordinate · junior · entry-level