Plain English Meaning
A drug that shrinks swollen tissue in the nose and sinuses so they can drain and let air pass through more easily.
Full Definition
A medication that reduces swelling of the mucous membranes lining the nose, sinuses, and Eustachian tubes by narrowing local blood vessels, thereby clearing blocked nasal passages and improving airflow and pressure equalization.
Context Anchor
Seen in aeromedical discussions about colds, sinus congestion, ear pressure, and whether a pilot should fly when sick or taking medicine.
Derivation
From Latin 'de-' (reverse, remove) plus 'congestion,' from Latin 'congestus' meaning 'piled up' or 'crowded together.' A decongestant literally undoes the piling-up of fluid and swelling in the airways.
Why Pilots Care
Using decongestants around flight time can affect pressure equalization in the ears and sinuses or introduce side effects that impact pilot performance.