dyke

Etymology 1

A variant of dike, from Northern Middle English dik and dike (“ditch”), from Old Norse díki (“ditch”). Influenced by Middle Dutch dijc (“ditch; dam”) and Middle Low German dīk (“dam”). See also ditch.

noun

1. (historical) A long, narrow hollow dug from the ground to serve as a boundary marker.
2. A long, narrow hollow dug from the ground to conduct water.
3. (dialect) Any navigable watercourse.
4. (dialect) Any watercourse.
5. (dialect) Any small body of water.
6. (obsolete) Any hollow dug into the ground.
7. (now chiefly Australia, slang) A place to urinate and defecate: an outhouse or lavatory.
   In Cubbaroo's dim distant past They built a double dyke. Back to back in the yard it stood An architectural dream in wood. 1977, Ian Slack-Smith, “The Passing of the Twin Seater”, in The Cubbaroo Tales
8. An embankment formed by the creation of a ditch.
9. A wall, especially (obsolete outside heraldry) a masoned city or castle wall.
   Inchbrakie gives for Arms, Or, a Dyke (or Wall) Feſsways, broke down in ſome places, and in Baſe a Roſe Gules, on a chief Sable three Eſcalops of the firſt. The Dyke (or Wall) here, is aſſumed not only to difference, but to perpetuate the valiant Action of Graham before mentioned; in throwing down the Wall and Ditch, which the Romans made betwixt Forth and Clyde, to keep out the Scots, … 1722, Alexander Nisbet, A System of Heraldry Speculative and Practical, page 82
   Wall, (sometimes called a dyke, fr. mur) : this is generally found in connection with castles or towns which are walled (muraillé). A wall of which kind should be masoned (fr. maçonné) and embattled (fr. crenellé), even though this be not specified. … Or, a dyke [or wall] fesswise [masoned proper] broken down in some places gules; … —Graham, Inchbrakie, Scotland [similar arms borne by Græme of Stapleton]. 1894, Henry Gough, James Parker, A Glossary of Terms Used in Heraldry, page 608
   The Galloway Dyke / In southwest Scotland there is a local style of dry stone dyke that is now recognized as 'the Galloway dyke', although when this pattern of was first developed, it was simply described as 'the sheep dyke'. 2023-02-21, Nick Aitken, Dry Stone Walling - Materials and Techniques, The Crowood Press
10. (now chiefly Scotland) A low embankment or stone wall serving as an enclosure and boundary marker.
    The Galloway Dyke / In southwest Scotland there is a local style of dry stone dyke that is now recognized as 'the Galloway dyke', although when this pattern of was first developed, it was simply described as 'the sheep dyke'. 2023-02-21, Nick Aitken, Dry Stone Walling - Materials and Techniques, The Crowood Press
11. (dialect) Any fence or hedge.
12. An earthwork raised to prevent inundation of low land by the sea or flooding rivers.
    The king of Texcuco advised the building of a great dike, so thick and strong as to keep out the water. 1891, Susan Hale, The Story of Nations: Mexico, page 100
13. (figurative) Any impediment, barrier, or difficulty.
14. A beaver's dam.
15. (dialect) A jetty; a pier.
16. A raised causeway.
17. (dialect, mining) A fissure in a rock stratum filled with intrusive rock; a fault.
18. (geology) A body of rock (usually igneous) originally filling a fissure but now often rising above the older stratum as it is eroded away.
    Their exact relationship to the host-rock is obscure but from their texture and observed metamorphic relationship they are thought to be intrusive dykes rather than intercalations of more basic lava. 1968, Transactions of the Geological Society of South Africa, page 148

verb

1. (transitive or intransitive) To dig, particularly to create a ditch.
2. (transitive) To surround with a ditch, to entrench.
3. (transitive, Scotland) To surround with a low dirt or stone wall.
4. (transitive or intransitive) To raise a protective earthwork against a sea or river.
5. (transitive) To scour a watercourse.
6. (transitive) To steep [fibers] within a watercourse.

Etymology 2

Uncertain. Attested since the 1940s (in Berrey and Van den Bark’s 1942 American Thesaurus of Slang) or 30s. Semantic development from dyke (“ditch”) has been proposed, and some sources from the 1890s are said to record dyke as slang for "vulva" and hedge of the dyke as slang for "pubic hair", but Green's Dictionary of Slang says this is not found in connection to lesbianism and Dictionary.com considers a connection unlikely. Bull dyke / bulldike is attested earlier, in reference to women since at least the 1920s (the 29 July 1892 Decatur Daily Review in Illinois mentions a woman who "won the affections of Harvey Neal, alias 'Bulldyke'", whose gender is unclear); compare dike (“noun: well-dressed man; verb: be well dressed”)), bulldyker, and bulldyking, which are all attested earlier than bare dyke, e.g. in Parke's 1906 Human Sexuality, in the speech of Philadelphians, and backcountry Black Americans. Compare bulldagger, attested since around the same time and used especially by Black women. Other linguists suggested that bull dyke(r) referred to strong Black women who dug dikes, or derived from bull + dick, perhaps in reference to Black men. It has also been suggested dyke is a shortening of morphodyke, from morphodite, from hermaphrodite, but the derivation may go in the other direction instead, with morphodyke being a blend of morphodite with the already-extant word dyke.

noun

1. (slang, usually derogatory, offensive) A lesbian, particularly one with masculine or butch traits or behavior.
2. (slang, usually derogatory, loosely, offensive) A non-heterosexual woman.