Emily Dickinson Lexicon

CO-AG'U-LATE, v.t. [L. coagulo; Fr. coaguler; It. coagulare; Sp. coagular. Usually considered as from cogo, con and ago. But probably the last component part of the word is the W. ceulaw; to curdle, the root of gelid and congeal.]

To concrete; to curdle; to congeal; to change from a fluid into a fixed substance, or solid mass; as, to coagulate blood; rennet coagulates milk. This word is generally applied to the change of fluids into substances, like curd or butter, of a moderate consistence, but not hard or impenetrable. – Bacon. Arbuthnot.