I. ˌən-dər-ˈnēth preposition
Etymology: Middle English undernethe, preposition & adverb, from Old English underneothan, from under + neothan below — more at beneath
Date: before 12th century
1.
a. : directly beneath
write the date underneath the address
b. : close under especially so as to be hidden
treachery lying underneath a mask of friendliness
wore a swimsuit underneath his slacks
2. : under subjection to
II. adverb
Date: before 12th century
1. : under or below an object or a surface : beneath
2. : on the lower side
• underneath adjective