(neurology, chiefly US) A genetic disorder caused by the presence of all or part of a third copy of chromosome 21 (a chromosomal excess), whereby the patients bear a certain resemblance to the Mongoloid race, such as a small head and tilted eyelids, and typically have a delay in cognitive ability and physical growth.

Used other than figuratively or idiomatically: see put, down. / (idiomatic) To insult, belittle, or demean. / (of money as deposit) To pay. / To halt, eliminate, stop, or squelch, often by force.

Alternative spelling of put-down

(idiomatic) To refuse, decline, or deny. / (idiomatic) To reduce the power, etc. of something by means of a control, such as the volume, heat, or light.

present participle of dumb down

(idiomatic, transitive) To convey some subject matter in simple terms, avoiding technical or academic language, especially in a way that is considered condescending.

Perfected; practiced ease and confidence.

(idiomatic) To consume (food) quickly or greedily, without regard for table manners.

(idiomatic) to examine information at another level or in greater detail; especially in a database, to navigate to a more detailed level or record

(of marching bands) an internal competition used to practice marching commands, in which the last person caught improperly executing a command wins