What does chill mean?
Chill is a versatile English word that functions primarily as a noun, verb, and informal adjective. In its oldest sense, a chill is a noticeable coldness in the air, or the shivering fit that comes from exposure to cold or from fever — hence phrases like 'catch a chill.' By extension, it describes a sudden sensation of fear or dread, as when 'a chill runs down your spine' during a frightening film. Since the late twentieth century, chill has taken on a prominent informal life: to 'chill out' means to relax or calm down, while 'chilling' can describe unhurried leisure time. As a slang adjective, calling someone or something 'chill' suggests they are easygoing, pleasant, or low-stress. This range — from physical cold to emotional calm — makes chill one of those compact words whose modern connotations are almost entirely positive, even though its literal roots lie in discomfort.
A feeling of coldness in the air; a shivering fit caused by cold or fever; a sudden feeling of fear or dread.
"She pulled her coat tighter against the evening chill."
Often used figuratively in 'a chill of fear' or 'cast a chill over the room.'
To make something cold or allow it to become cold; informally, to relax or spend time idly.
"Chill the wine in the fridge before serving."
The informal sense 'to relax' is common in casual speech: 'Just chilling at home tonight.'
(Informal) Relaxed and easygoing in manner; pleasantly unhurried or low-key.
"The party had a really chill atmosphere."
The plural typically refers to repeated episodes of shivering, especially as a symptom of illness ('fever and chills').
"The flu left him with fever and chills for three days."
The same little word that once described medieval fever shivers now powers an entire lifestyle brand of doing absolutely nothing.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of chill
Chill descends from the Old English verb 'ciele' or noun 'cele,' related to 'calan' (to be cold), which also gives us 'cool' and 'cold' within the Germanic family. The word has been part of English since its earliest recorded periods, originally denoting both coldness itself and the shivering it produces. The figurative sense of a 'chill' of fear developed naturally from the physical shiver. Its modern slang use meaning 'to relax' emerged in American English around the 1970s–80s, notably in African American vernacular usage before spreading widely through popular culture.
Related word forms
How chill is actually used
'Chill' as a verb meaning 'to relax' is firmly informal and widespread in everyday speech across British and American English. As a slang adjective describing someone easygoing, it's casual register. The older senses relating to coldness and illness are neutral in tone.
Easily confused with chill
'Chile' refers to a hot pepper or the country Chile, while 'chill' means cold or relaxed.
'Chilli' (British spelling of chili) is a spicy pepper, whereas 'chill' relates to coldness or relaxation.