Definify.com
Webster 1913 Edition
Synovial
Syn-o′vi-al
,Adj.
 [Cf. F. 
synovial
.] (Anat.) 
Of or pertaining to synovia; secreting synovia. 
Synovial capsule
, a closed sac of synovial membrane situated between the articular surfaces at diarthrodial joints. 
– Synovial fluid
, synovia. 
– Synovial membrane
, the dense and very smooth connective tissue membrane which secretes synovia and surrounds synovial capsules and other synovial cavities.