What does "synovial" mean?

Synovial: 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.