What is "disclination"

n. 1 (context physics English) Any of several defects in rotational symmetry, especially in the orientation of the molecules of a liquid crystal; related to dislocation and dispiration. 2 (context medicine English) extorsion

A disclination is a line defect in which rotational symmetry is violated. In analogy with dislocations in crystals, the term, disinclination, for liquid crystals first used by F. C. Frank and since then has been modified to its current usage, disclination. It is a defect in the orientation of director whereas a dislocation is a defect in positional order.