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cockroach or roach, name applied to some 4,600 species of flat-bodied, oval insects in the order Blattodea. Cockroaches have long antennae, long legs adapted to running, and a flat extension of the upper body wall that conceals the head. They range from 1-4 in. to 3 in. (.6–7.6 cm) in length. Some cockroaches have two pairs of well-developed wings, the front pair covering the hind pair when at rest; others have reduced wings or none at all. In some species only the wings of the female are reduced or absent. Many species are able to fly well, although the familiar household species do not fly. Most cockroaches are shiny brown or black, but bright yellows, reds, and greens occur in some tropical species.

Cockroaches are night-active insects and most live in damp places; most are omnivorous scavengers. They are worldwide in distribution but are most numerous in the tropics. Most species live in the wild in their native regions, e.g., the wood cockroaches, species of the genus Parcoblatta, found under forest litter in the NE United States.

A few tropical and subtropical species that have been introduced into the temperate zone have become residents in human homes, where they multiply rapidly and are serious pests. They invade food supplies and emit foul-smelling glandular secretions. Their shape enables them to use tiny cracks as hiding places. They are popularly believed to be carriers of human diseases, although this has not been proved.

Cockroaches reproduce sexually. Their eggs are encased in capsules called oothecae, which in some species remain attached to the abdomen of the female until the eggs hatch. In a few species the ootheca is retained within the body of the female and the young are born live. Young resemble the adults except in size.

The large, dark Oriental cockroach, Blatta orientalis, is a cosmopolitan household species. The smaller German cockroach, or Croton bug, Blattella germanica, native to Europe, is the common urban cockroach of the NE United States. The American cockroach, Periplaneta americana, is a large light-reddish species that invades houses in the S United States.

The group as a whole is extremely old; fossil evidence indicates its extreme abundance during the Carboniferous period, about 350 million years ago. These ancient cockroaches were able to fly and were probably the first flying animals. Cockroaches are classified in several families of the phylum Arthropoda, class Insecta, order Blattodea.

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(invertebrate zoology)
An insect of the family Blattidae; the body is wide and flat, the anterior part of the thorax projects over the head, and antennae are long and filiform, with many segments. Also known as cockroach.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


1. a European freshwater cyprinid food fish, Rutilus rutilus, having a deep compressed body and reddish ventral and tail fins
2. any of various similar fishes


1. short for cockroach
2. Slang the butt of a cannabis cigarette


3 Nautical
1. the amount by which the leech of a fore-and-aft sail projects beyond an imaginary straight line between the clew and the head
2. the curve at the foot of a square sail
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005


A Bell Labs term meaning destroy, especially of a data structure. Hardware gets toasted or fried, software gets roached.

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References in periodicals archive ?
To bat: R Chase, S Hetmyer, J Holder, +J Hamilton, R Cornwall, K Roach, S Gabriel
He was hit on the right elbow by Roach, and in the groin by Gabriel.
Buboy, I don't have the power to do that but my suggestion to him would be honest," said Roach as he was about to train heavy-handed African super-bantamweight Isaac Dogboe.
Roach said Pacquiao complained of blurry vision at the post-fight presser, either caused by allergy to Vaseline the lubricant applied to the face to prevent cuts or something else.
Roach, wholly impressed, cried the odds in the welterweight bout, wherein Pacquiao has been installed the underdog, have emboldened him to try some betting.
Roach's filings and other evidence "demonstrate that there is no genuine issue of material fact as to any of the stated claims, and Roach is entitled to judgment as a matter of law," said Roach's attorney, David Wilson of Friday Eldredge & Clark of Little Rock, in his motion for partial summary judgment.
Pontypridd Coroners' Court heard yesterday that Mr Roach had spent the evening of September 1 last year drinking in various bars with his partner, Gemma Evans.
Mr Roach had consumed alcohol, MDMA and amphetamines on the night when he fell near the Porthcawl Lifeboat Station and died three days later in hospital.
Peter Oshiro of the Health Department said, "Roach infestations can come from a lot of different things.
Gut bacteria in young German cockroaches (Blattella germanica) produce fragrant compounds that, when excreted, attract other roaches, researchers report online December 7 in the Proceedings of the National Academy of Sciences.
The German cockroach is the most common types of the roach. German roaches can breed at a rate of around 6 generations per year.
From the Squamish Powwow just outside of Victoria, British Columbia, to the Art and Culture Center of Santa Fe, New Mexico, to the Spirit of the Wolf powwow in Albany, NewYork; the roach has been adopted as a near necessity for most dance outfits.