Emily Dickinson Lexicon

DIKE, n. [Sax. dic; Sw. dike; Dan. dige; D. dyk; G. deich; Ir. diog; Scot. dike, dyk; Fr. digue; Sp. dique; from digging. See Dig. It is radically the same word as ditch, and this is its primary sense; but by an easy transition, it came to signify also the bank formed by digging and throwing up earth. Intrenchment is sometimes used both for a ditch and a rampart.]

1. A ditch; an excavation made in the earth by digging, of greater length than breadth, intended as a reservoir of water, a drain, or for other purpose. – Dryden. Pope.
2. A mound of earth, of stones, or of other materials, intended to prevent low lands from being inundated by the sea or river. The low countries of Holland are thus defended by dikes.
3. A vein of basalt, greenstone or other stony substance; or an intrusion of melted matter into rents or fissures of rocks. – Cleaveland. Mantell.