What does exhalation mean?
Exhalation is the act of breathing out — the phase of respiration in which air passes from the lungs into the atmosphere. The word also extends beyond physiology: it can describe any vapor, odor, or emanation that rises from a source, as when steam or fumes are said to be an exhalation of the ground or of some process. In ordinary use it most often appears in phrases like 'a long exhalation' or 'a deep exhalation', describing the deliberate release of breath that accompanies relief, calm, or exertion — think of a slow exhale at the end of a yoga pose. Though closely related to the common verb 'exhale', the noun carries a slightly more formal or clinical tone, and everyday conversation usually prefers simply 'breath'. It pairs naturally with its opposite, inhalation, and belongs to a small family of words derived from the Latin verb halare, 'to breathe'.
The act or process of exhaling; air breathed out from the lungs.
"The swimmer timed each exhalation with the rhythm of her strokes."
In medical and scientific writing, 'exhalation' and 'expiration' are largely interchangeable.
Something breathed out or emitted, such as a vapor, odor, or emanation.
"An exhalation of mist rose from the valley floor at dawn."
This extended sense is somewhat literary and less common than the respiratory meaning.
Regular plural, used when referring to multiple instances of breathing out or multiple vapors/emanations.
"Her slow, measured exhalations calmed the anxious patient."
Every breath you take is a two-act play — and exhalation is the act everyone forgets to applaud.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of exhalation
Exhalation comes from the Latin exhalatio, formed from exhalare, meaning 'to breathe out' — a compound of ex- ('out') and halare ('to breathe'). The word passed into English via late Middle English and early Modern English, becoming established by around the early 17th century. Its Latin root halare also gave English the words exhale, inhale, and halitosis, all sharing the core sense of breath.
Related word forms
How exhalation is actually used
Somewhat formal or technical in register; everyday speech more often uses the simpler word 'breath' (as in 'let out a breath'). In scientific and medical contexts, 'exhalation' is standard, sometimes used interchangeably with 'expiration'.
Easily confused with exhalation
Inhalation is the act of breathing in, while exhalation is the act of breathing out.