To sustain someone or something is to provide what is needed for that person or thing to exist or continue. Sustain also means "to hold up the weight of," "to suffer or endure," or "to confirm or prove." In legal contexts, to sustain something is to decide or state that it is proper, legal, or fair.

// Hope sustained us during that difficult time.

// The shed roof collapsed, unable to sustain the weight of all the snow.

// The athlete sustained serious injuries during last week's game.

See the entry >

"Pushing fallen leaves into garden beds to insulate plants and nourish the soil will also shelter hibernating insects that, in turn, will sustain ground-feeding birds. It's much better for the ecosystem—and easier for the gardener—than bagging them up and sending them to a landfill." — Jessica Damiano, The Chicago Daily Herald, 12 Oct. 2025

The word sustain is both handy and hardy. Its use has been sustained since the days of Middle English (it traces back to the Latin verb sustinēre meaning "to hold up" or "to sustain") by its utility across a variety of consequential subjects, from environmental protections to legal proceedings to medical reports. The word is so prevalent and so varied in its application, in fact, that it enjoys sustained high ranking as one of our top lookups—evidence of our readers' sustained commitment to, well, sustaining themselves with information about words.