The displacement of parts of rocks or portions of strata from the situation which they originally occupied. Slips, faults, and the like, are dislocations.
(materials) A linear defect in a crystal lattice. Because dislocations can shift within the crystal lattice, they tend to weaken the material, compared to a perfect crystal.
(grammar) A sentence structure in which a constituent that could otherwise be either an argument or an adjunct of a clause occurs outside of and adjacent to the clause boundaries. For example, the sentence, "My father, he is a good man", is a left dislocation because the constituent "My father" has been moved to the left of the clause "he is a good man". See dislocation.