Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Unified Medical Language System® (UMLS®)

SPECIALIST Lexicon and Lexical Tools

The SPECIALIST Lexicon is an English lexicon containing many words from the biomedical domain. Words are selected for lexical coding from a variety of sources including MEDLINE abstracts, Dorland's Illustrated Medical Dictionary and the general English vocabulary. The majority of the words are nouns.

The lexicon consists of a set of lexical entries. Each entry represents a word (lexical item). The entry covers one or more spellings in a particular part of speech and describes the morphologic, orthographic and syntactic properties of a word.

The Lexical Tools are a collection of java programs that process natural language words and terms. The lexical tools include a normalizer, a word index generator, and a lexical variant generator. Together The SPECIALIST Lexicon and The Lexical Tools allow users to develop Natural Language Processing programs.

Last Reviewed: July 29, 2016