Bursa

bur′sa, n. a pouch or sac, esp. a synovial cavity formed where tendons pa over the harder parts of the body:— pl. Bur′sæ (-sē).— adj. Bur′sal .— ns. Bursā′lis , a muscle moving the nictitating membrane, as in birds; Bursal′ogy , knowledge about the bursæ. [See Bursar .]