Definition of clotter:
(n) :
(medicine, informal) One who studies the clotting of blood and blood clotting disorders; hematologist.
(n) :
Something that induces (something such as blood or cream) to clot.
(n) :
One whose blood or other tissue forms clots.
(n) :
One who clots for eels; One who fishes with a pole or cord that is baited with a clot of worm strung on worsted or similar material, which gets tangled in the teeth of the eel.
(n) :
(medicine, obsolete) A clot; a mass of clotted blood.
(n) :
(by extension, obsolete) A clump, clod, or mass.