under or below an object or a surface; "we could see the original painting underneath" beneath by way of support; "a house with a good foundation underneath" lower down on the page; "diagrams with figures underneath" on the lower or downward side; "a chest of drawers all scratched underneath
The part of something which is underneath is the part which normally touches the ground or faces towards the ground. Check the actual construction of the chair by looking underneath His bare feet were smooth on top and rough-skinned underneath. Underneath is also an adjective. Some objects had got entangled with the underneath mechanism of the engine. Underneath is also a noun. Now I know what the underneath of a car looks like
You use underneath when talking about feelings and emotions that people do not show in their behaviour. He was as violent as Nick underneath Underneath is also a preposition. Underneath his outgoing behaviour Luke was shy. the underneath the bottom surface of something, or the part of something that is below or under something else = the underside