Thesauri

EUROVOC – Thesaurus
"tesauro multilingue que cobre todos os domínios da actividade das Comunidades Europeias”

AGROVOC – Thesaurus
”It is a multilingual structured and controlled vocabulary designed to cover the terminology of all subject fields of agriculture, forestry, fisheries, food and related domains(…)”

Library of Congress Thesauri

National Library of Medicine classification

Criminological Thesaurus
United Nations Interregional Crime and Justice Research Institute

The Alcohol and Other Drug Thesaurus

Cook’s Thesaurus

The Astronomy Thesaurus

UNBIS Thesaurus – United Nations Bibliographic Information System

Thesaurus.com

Online Spanish Thesaurus, Spanish Dictionary of Synonyms and Anthonyms