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(ŭrt′ĭ-kāt″) [L. urticare, to sting] 1. To produce urticaria. 2. Marked by the appearance of wheals.


(ū-roo′shē-ol″) [Japanese urushi, lac + -ol] The principal toxic irritant substance of plants such as poison ivy, which produces characteristic severe dermatitis on contact.


ultrasound;. undetermined significance.


(ūz″ă-bil′ĭt-ē) A design characteristic pertaining to the ease with which people can employ tools and processes to perform goal-related tasks. Included in the characteristics are elements such as ease of learning, recall, satisfaction, and efficiency.


United States Atomic Energy Commission.


United States Adopted Names (for drugs).

USAN and the USP Dictionary of Drug Names

A dictionary of nonproprietary names, brand names, code designations, and Chemical Abstracts Service registry numbers for drugs. SEE: United States Adopted Names.


[Acronym for u(ltra)s(onic) c(ardiac) o(utput) m(onitor)] A noninvasive device that measures cardiac output.


United States Department of Agriculture.

USDA organic

A USDA designation for food that specifies that 95% of its components are organic.

use of force

Interpersonal violence, esp. by police officers, members of the military, or other authorized members of the legal system or the state.


(ūz′net″) A worldwide collection of user-submitted notes or messages on various subjects that are posted to servers on the Internet.

Usher syndrome

(ŭsh′ĕr) [Charles Howard Usher, Brit. ophthalmologist, 1865–1942] An autosomal recessive disorder marked by a combination of congenital sensorineural deafness and retinitis pigmentosa that results in a gradual loss of vision. One variant of the syndrome also interferes with normal balance. SEE: retinitis pigmentosa.

USP, US Phar

United States Pharmacopeia; United States Pharmacopeial Convention, Inc.


United States Public Health Service.


United States Pharmacopeia–National Formulary.


United States Psychiatric Rehabilitation Association.


United States Preventive Services Task Force.


(ŭs-tĭ-lā′gō) [L. ustilago, the name of a plant] A genus of approx. 200 parasitic fungi, esp. U. maydis, that form powdery, black masses of spores (smut) on cereal plants and make them unfit to eat.


(oot′ă) [A local name in Peru] American leishmaniasis.

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