roach

• (Received Pronunciation) IPA^(key): /ɹəʊtʃ/
• (US) IPA^(key): /ɹoʊtʃ/
• Rhymes: -əʊtʃ

From Old French roche, from Middle Low German roche, ruche (“ray (fish)”); cognate with German Rochen (“ray (fish)”).

roach (plural roach)

1. Certain members of the fish family Cyprinidae, including:
   1. Species in the genus Rutilus, especially:
      1. The common roach (Rutilus rutilus)
   2. The California roach, of the monotypic genus Hesperoleucus

• Albanian roach (Pachychilon pictum, Leucos basak)
• Black Sea roach (Rutilus lacustris)
• blue roach (Scardinius erythrophthalmus)
• California roach (Hesperoleucus symmetricus)
• common roach Rutilus rutilus)

Back-formation from cockroach, as if it were a compound.

roach (plural roaches)

1. (US) A cockroach.

• brown-banded roach (Supella supellectilium)
• dubia roach (Blaptica dubia)
• Madeira roach (Leucophaea maderae)
• oriental roach (Blatta orientalis)
• sea roach (Ligia oceanica, Ligia exotica)
• wharf roach (Ligia exotica)

Apparently from extended or figurative use of roach (“Cyprinidae”), above. Compare the adjective roached (“styled so that the mane stands up from the neck”).

roach (plural roaches)

1. (nautical) An extra curve of material added to the leech edge of a sail to increase the sail area.
2. A kind of headdress worn by some of the indigenous peoples of North America.

Extended or jocular use of roach (“cockroach”), above. Attested since the 1930s.

roach (plural roaches)

1. (US, slang, smoking) Marijuana; cannabis used as a drug.
   • 1957, Alfred Maund, The Big Boxcar, Urbana: University of Illinois Press, →ISBN, page 106:

     In his half hour of free time between brooms it was Willie's custom to smoke his lunch in an alleyway. He'd take just half a roach, only enough to make him feel a new day was starting, no more no less.

2. (US, slang, smoking) A butt of a marijuana cigarette.
3. (Britain, slang, smoking) The filter of a rolled cigarette or joint, made from card or paper.

Variant of roche (“rock”). Attested since the seventeenth century.

roach (plural roaches)

1. (Britain, obsolete, mining) A bed or stratum of some mineral.
   • 1749, Rog. Mostyn, “Mineralogy”, in Philosophical Transactions and Collections to the End of the Year, volume II, London: Royal Society, OCLC 149630598, page 379:

     After long Working of this Coal, it was found upon the rising Grounds, that there lay another Roach of Coal, at the Depth of 14 Yards under it

2. (Britain, regional) Gritty or coarse rock; especially Portland stone or similar limestone.
   • 1841, C.H. Smith, “Lithology; or Observations on Stone for Building”, in The Surveyor, Engineer, and Architect, OCLC 33911436, page 13:

     The roach, both of the top and bottom beds, is always imperceptibly incorporated with the freestone, which is invariable situated beneath it.

• Jonathon Green (2016), “roach, n.”, in Green's Dictionary of Slang‎
• “roach, n.2.”, in OED Online ⁠, Oxford: Oxford University Press, launched 2000.
• “roach, n.3.”, in OED Online ⁠, Oxford: Oxford University Press, launched 2000.
• “roach, n.4.”, in OED Online ⁠, Oxford: Oxford University Press, launched 2000.

• Rocha, achor, archo-, corah, ochra, orach