undersurfaces
Areas facing down
Undersurfaces are the bottom or lower sides of things—the parts facing downward or hidden from typical view.
The word appears most often in technical or scientific contexts: the undersurfaces of leaves, the undersurfaces of aircraft wings.
The undersurfaces of the rocks were covered in algae.
Lower surface of something
Foundational layer beneath
- subfloorBase beneath finished flooring
- subbaseFoundation beneath a surface
- substructureSupporting base beneath
- foundationUnderlying support structure
bedrock · groundwork · base · footing · underframe · sublayer · baseplate
Made invisible deliberately
- obscuredMade hard to perceive
- unseenNot perceived visually
- undetectedNot discovered yet
- unrevealedNot made public
latent · buried · unexposed · overlooked · unexamined · unnoticed · neglected · invisible
Protective vehicle underbody layer
- primerPreparatory coat or guide
- sealantGap-blocking substance
- rustproofingTreating metal against decay
- protectiveServing to guard
treatment · finish · application · waterproofing · anti-corrosion · preservative
underside
Lower surface of something
substratum
Foundational layer beneath
- subfloorBase beneath finished flooring
- subbaseFoundation beneath a surface
- substructureSupporting base beneath
foundation · bedrock · groundwork · base · footing · underframe · sublayer · baseplate
concealed
Made invisible deliberately
- obscuredMade hard to perceive
- unseenNot perceived visually
- undetectedNot discovered yet
unrevealed · latent · buried · unexposed · overlooked · unexamined · unnoticed · neglected · invisible · below
undercoating
Protective vehicle underbody layer
- primerPreparatory coat or guide
- sealantGap-blocking substance
- rustproofingTreating metal against decay
protective · treatment · finish · application · waterproofing · anti-corrosion · preservative