hydrarthrosis

English Thesaurus

1. inflammation and swelling of a movable joint because of excess synovial fluid (noun.state)

hypernym	:	inflammation, redness, rubor,
definition	:	a response of body tissues to injury or irritation; characterized by pain and swelling and redness and heat (noun.state)

hyponym	:	water on the knee,
definition	:	hydrarthrosis affecting the knee (noun.state)