ad·e·noids / ˈadnˌoidz/ • pl. n. a mass of enlarged lymphatic tissue between the back of the nose and the throat, often hindering speaking and breathing in young children.DERIVATIVES: ad·e·noi·dal / ˌadnˈoidl/ adj.

adenoids Masses of lymph tissue in the upper part of the pharynx (throat) behind the nose; part of a child's defences against disease, they often enlarge after infections in the area. Adenoids normally disappear by the age of ten.

adenoids (nasopharyngeal tonsil) (ad-in-oidz) n. a collection of lymphatic tissue in the nasopharynx. Enlargement of the adenoids can cause obstruction to breathing through the nose and can block the Eustachian tubes, causing glue ear.