What does swell mean?
To swell means to become larger, fuller, or more intense, often in a gradual way. A person’s confidence, an organization’s membership, a wave, or the volume of a crowd may all swell. The word can also describe a physical expansion, such as when dough swells as it rises or when the sea swells under a storm. As a noun, a swell is a wave, surge, or increase in something such as popularity or activity; a swell of anger or excitement is a common expression. In informal American English, particularly in older speech, swell is also an adjective meaning excellent or impressive: “That’s a swell idea.” These meanings are related by the idea of growth or expansion, whether literal, emotional, or figurative.
To become larger, fuller, more numerous, or more intense.
"The crowd began to swell as the band took the stage."
A wave or surge, especially of water; a gradual increase in quantity, intensity, or popularity.
"A swell of applause rose from the audience."
Excellent or impressive; in older informal usage, fashionable or stylish.
"We had a swell time at the concert."
Informal and somewhat dated, especially in American English.
Used when referring to individual waves or surges, or to separate increases in a quantity or intensity.
"Long swells rolled toward the shore."
The sea does not merely rise: it swells, as though the waves are gathering themselves into a greater force.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does swell come from?
The word comes from Middle English, with forms related to Old English swellan and swellan, meaning to rise, expand, or be puffed out. It ultimately belongs to a Germanic root associated with swelling or swelling up. The modern English adjective meanings developed by extension from the older sense of something impressive or grand, while the noun developed from the idea of a rising wave or surge.
Related word forms
How swell is actually used
As a verb, swell is commonly intransitive and can describe physical size, quantities, emotions, or groups of people. As an adjective, its meanings meaning excellent or fashionable are informal and somewhat dated, especially in American English.