Di-ær'e-sīs or Di-ēr'e-sīs, n.
n.; pl. DI-ÆR'/E-SĒS, or DI-ĒR'/E-SĒS. [Gr. διαίρεσις, from διαιρεῖν, to divide, from διά, through, asunder, and αἱρεῖν, to take, to seize; Lat. diaeresis, Fr. diérèse.]
Sense 1. (Gram.) (a.) The separation or resolution of one syllable into two. (b.) A mark consisting of two dots, thus [¨], placed over the second of two adjacent vowels, to denote that they are to be pronounced as distinct letters; as, coöperate.
Sense 2. (Surg.) The operation of dividing any part of the body. Dunglison.