underside

noun

un·​der·​side ˈən-dər-ˌsīd 

ˌən-dər-ˈsīd

1

: the side or surface lying underneath

2

: a side usually hidden from sight

specifically : the more unpleasant or reprehensible side

the underside of politics

Synonyms of underside

• bottom

Examples of underside in a Sentence

the underside of the table

The book explores the underside of human nature.

Recent Examples on the Web

Check for Pests Examine the vines, the undersides of the leaves, and any new growth for spider mites, aphids, and mealybugs. —Leanne Potts, Better Homes & Gardens, 10 Nov. 2025

Stengel’s shot, off the underside of the crossbar in the match’s dying moments, put an end to the Current’s season. —Daniel Sperry, Kansas City Star, 9 Nov. 2025

Golden mussels clog the thruster and decorate the underside of his dinghies. —Calmatters, Mercury News, 6 Nov. 2025

Both tortoises were microchipped and the Egyptian tortoise was said to have a prominent scar on its underside, Indiana State Police said in a press release. —Meredith Deliso, ABC News, 28 Oct. 2025

Word History

First Known Use

1660, in the meaning defined at sense 1

Rhymes for underside

• actinide
• aldehyde
• alkoxide
• alongside
• amplified
• arsenide
• beautified
• biocide
• butoxide
• calcified
• ceramide
• certified

Kids Definition

underside

noun

un·​der·​side ˈən-dər-ˌsīd 

ˌən-dər-ˈsīd

: the side or part lying underneath