Thrombosis \Throm*bo"sis\, n. [NL. See Thrombus.]

(Med.) The obstruction of a blood vessel by a clot formed at the site of obstruction; -- distinguished from embolism, which is produced by a clot or foreign body brought from a distance. -- Throm*bot"ic, a.

Source: Webster's Revised Unabridged Dictionary (1913)