Emily Dickinson Lexicon

DI-LATE', v.t. [L. dilato; di and latus, wide; Fr. dilater; It. dilatare; Sp. dilatar. See Delay.]

1. To expand; to distend; to enlarge or extend in all directions; opposed to contract. The air dilates the lungs; air is dilated by rarefaction.
2. To enlarge; to relate at large; to tell copiously or diffusely; as, to dilate upon the policy of a measure. In this sense, it is generally used intransitively. Spenser and Shakspeare have used it in a transitive sense; as, to dilate a theme.