http://www.w3.org/2004/02/skos/core#definition

used by 11:

• aksworg
• courts-thesaurus
• enel-open-data-dcat
• esd-toolkit
• event-media
• global-hunger-index
• global-hunger-index-2011
• lcsh
• nalt
• stitch-rameau
• thesaurus-bncf