adenoid

noun

ad·​e·​noid ˈa-də-ˌnȯid 

ˈad-ˌnȯid

: either of two abnormally enlarged masses of lymphoid tissue at the back of the pharynx that usually obstruct the nasal and ear passages

also : such a mass when not abnormally enlarged

—usually used in plural

Examples of adenoid in a Sentence

Recent Examples on the Web

But there are also lingual tonsils (base of the tongue), tubal (around the opening of the Eustachian tube in the nasopharynx (upper part of cavity behind nose and mouth) and adenoid (high up in throat behind nose). —Scott Lafee, San Diego Union-Tribune, 19 May 2026

Lueloff reported in the 1970s on patients who two decades earlier had received radiation treatment for tonsils and adenoids but then, years later, were diagnosed with thyroid cancer. —Bob Goldsborough, Chicago Tribune, 16 Mar. 2026

The 5-year-old boy was scheduled to have his adenoids (glands located behind the nasal passage) removed on Thursday, Dec. 4, according to the reports. —Sam Gillette, PEOPLE, 5 Dec. 2025

Then, when Morgan was 7 and Allison just 5, doctors discovered polyps on Allison’s adenoids. —Jordan Greene, People.com, 24 June 2025

Word History

Etymology

earlier, "a benign tumor (as of the breast)," borrowed from French adénoïde, short for tumeur adénoïde, literally, "adenoid (i.e., glandular) tumor" — more at adenoid entry 2

First Known Use

circa 1890, in the meaning defined above

Rhymes for adenoid

• alkaloid
• amoeboid
• amyloid
• aneroid
• arachnoid
• asteroid
• benzenoid
• carcinoid
• celluloid
• coronoid
• humanoid
• mongoloid

Kids Definition

adenoid

1 of 2 noun

ad·​e·​noid ˈad-ᵊn-ˌȯid 

ˈad-ˌnȯid

: either of two masses of tissue at the back of the pharynx that usually interfere with breathing when abnormally enlarged

—usually used in plural

adenoid

2 of 2 adjective

1

: of or relating to the adenoids

2

: relating to or affected with abnormally enlarged adenoids

Medical Definition

adenoid

1 of 2 adjective

ad·​e·​noid ˈad-ᵊn-ˌȯid, ˈad-ˌnȯid 

1

: of, like, or relating to glands or glandular tissue

especially : like or belonging to lymphoid tissue

2

: of or relating to the adenoids

in the adenoid region of the pharynx

3

a

: of, relating to, or affected with abnormally enlarged adenoids

a severe adenoid condition

an adenoid patient

b

: characteristic of one affected with abnormally enlarged adenoids

adenoid facies

adenoid

2 of 2 noun

1

: an abnormally enlarged mass of lymphoid tissue at the back of the pharynx characteristically obstructing the nasal and ear passages and inducing mouth breathing, nasality, postnasal discharge, and dullness of facial expression

—usually used in plural

2

: pharyngeal tonsil