roach

• (Received Pronunciation) IPA^(key): /ɹəʊtʃ/
• (US) IPA^(key): /ɹoʊt͡ʃ/

• Audio (General Australian):

  (file)

• Rhymes: -əʊtʃ

From Middle English roche, from Old French roche, from Middle Low German roche, ruche (“ray (fish)”), from Old Saxon *rūh, possibly from Proto-Germanic *rūhaz (“rough”).

Cognate with Old English ruhha ("a ray"; > Middle English rouhe, rohȝe), German Rochen (“ray (fish)”).

roach (plural roach)

2. Certain members of the fish family Cyprinidae, including:
   1. Any fish of species in the genus Rutilus, especially:
      1. A common roach (Rutilus rutilus)
   2. A 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)
• Caspian roach (Rutilus caspicus)
• common roach (Rutilus rutilus)

• Rutilus on Wikimedia Commons.Wikimedia Commons

Back-formation from cockroach, as if it were a compound. Marijuana-related meanings by similarity of appearance of the butt, attested since the 1930s.

roach (plural roaches)

2. (US) A cockroach.
3. (US, slang, smoking) The butt of a marijuana cigarette.
4. (US, slang, smoking) An entire marijuana cigarette, blunt, or joint.
   • 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.

5. (UK, slang, smoking) The filter of a rolled cigarette or joint, made from card or paper.
   • 2000, Zadie Smith, White Teeth, London: Penguin Books, published 2001, →ISBN, page 292:

     Last toke is the yellowing fabric of the roach, containing the stuff that is less than tobacco.

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

(This etymology is missing or incomplete. Please add to it, or discuss it at the Etymology scriptorium.)

roach (plural roaches)

2. (nautical) Sail material that forms a concave curve rather than straight leech (aft edge) of a sail to increase the sail area over that of a simple triangular sail.
3. A haircut or a similar-looking kind of headdress worn by some of the indigenous peoples of North America, often red.

• roach-backed

roach (third-person singular simple present roaches, present participle roaching, simple past and past participle roached)

1. (transitive) To cut or shave off the mane of a horse so that the remaining hair stands up on the neck.
2. (transitive, by extension) To cut a person's hair so that it stands straight up.

• roached

• Roach (headdress) on Wikipedia.Wikipedia
• Category:Roaches (headdress) on Wikimedia Commons.Wikimedia Commons

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

roach (plural roaches)

2. (UK, 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, 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

3. (UK, 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, page 13:

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

• “roach n.”, in Green’s Dictionary of Slang, Jonathon Green, 2016–present
• “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.
• “roach”, in OneLook Dictionary Search.

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