This is an irregular feature - both in frequency and oddness - dedicated to a word I came across that I have never previously used.
adj. Situated beneath or on the underside of the tongue.
n. A sublingual part, such as a gland, artery, or duct.
Sublingual, from the Latin words for 'under the tongue', refers to a pharmacological method of medcinal delivery in which certain drugs enter the bloodstream via absorption under the tongue.
Sublingual absorption has certain advantages over swallowing medicine. This route is often faster, and a drug that enters the body sublingually will only come into contact with saliva enzymes prior to entry into the bloodstream. Swallowed medications face the hostile environment of the gastrointestinal tract, especially the corrosive properties of the hydrochloric acid produced by the stomach.