let blood

let blood (third-person singular simple present lets blood, present participle letting blood, simple past and past participle let blood)

1. (transitive, now archaic or historical) To extract blood from (a person, part of the body etc.). [from 9th c.]
   • 1598, William Shakespeare,Love's Labours Lost:

     Is the foole sicke […] Alacke, let it blood.

   • 1751, Tobias Smollett, The Adventures of Peregrine Pickle, vol. III, ch. 84:

     The Swiss […] let him blood immediately, without hesitation, being always provided with a case of lancets, against all accidents on the road.

2. (intransitive, now archaic or historical) To bleed someone; to extract blood from a person, part of the body etc. for supposed therapeutic purposes, especially by phlebotomy. [from 10th c.]
3. (figurative) To make (someone or something) bleed, in a general sense; to cut; to kill. [from 13th c.]

• bloodlet
• bloodletting