Merriam-Webster's Collegiate® Dictionary, 11th Edition
JOY
I. noun
Etymology: Middle English, from Anglo-French joie, from Latin gaudia, plural of gaudium, from gaudēre to rejoice; probably akin to Greek gēthein to rejoice
Date: 13th century
1. the emotion evoked by well-being, success, or good fortune or by the prospect of possessing what one desires ; delight , the expression or exhibition of such emotion ; gaiety , a state of happiness or felicity ; bliss , a source or cause of delight, joyless adjective joylessly adverb joylessness noun
II. verb
Date: 14th century
intransitive verb to experience great pleasure or delight ; rejoice , transitive verb gladden , enjoy