| opercular part | One of the three small cortical convolutions together forming a cover for the insular region. Opercular convolutions are frontal, temporal, and parietal. Synonym: pars opercularis. (05 Mar 2000) |
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| operculated | 1. <botany> Closed by a lid or cover, as the capsules of the mosses. 2. <zoology> Having an operculum, or an apparatus for protecting the gills; said of shells and of fishes. Origin: L. Operculatus, p.p. Of operculare to furnish with a lid, fr. Operculum lid. Source: Websters Dictionary (01 Mar 1998) |
| operculiferous | <zoology> Bearing an operculum. Origin: Operculum. Source: Websters Dictionary (01 Mar 1998) |
| operculigenous | <marine biology, zoology> Producing an operculum; said of the foot, or part of the foot, of certain mollusks. Origin: Operculum + -genous. (19 Mar 1998) |
| operculitis | Originating under an operculum. Origin: operculum + G. -itis, inflammation (05 Mar 2000) |
| operculum | A lid or cover becoming detached at maturity by abscission, in Eucalyptus (for example), a cap covering the bud and formed by fusion or cohesion of perianth parts. (09 Oct 1997) |
| operculum ilei | A thickening of circular musculature at the free margin of the ileal papilla. Synonym: ileocaecocolic sphincter, marginal sphincter, operculum ilei, Varolius' sphincter. (05 Mar 2000) |
| operon | <molecular biology> Groups of bacterial genes with a common promotor, that are controlled as a unit and produce mRNA as a single piece, polycistronic messenger. An operon consists of two or more structural genes, which usually code for proteins with related metabolic functions and associated control elements that regulate the transcription of the structural genes. The first described example was the lac operon. (18 Nov 1997) |
| ophelic | <chemistry> Of, pertaining to, or designating, a substance (called ophelic acid) extracted from a plant (Ophelia) of the Gentian family as a bitter yellowish sirup, used in India as a febrifuge and tonic. Source: Websters Dictionary (01 Mar 1998) |
| ophiasis | A form of alopecia areata in which the loss of hair occurs in bands along the scalp margin partially or completely encircling the head. Origin: G., fr. Ophis, snake (05 Mar 2000) |
| ophidia | <zoology> The order of reptiles which includes the serpents. The most important divisions are: the Solenoglypha, having erectile perforated fangs, as the rattlesnake; the Proteroglypha, or elapine serpents, having permanently erect fang, as the cobra; the Asinea, or colubrine serpents, which are destitute of fangs; and the Opoterodonta, or Epanodonta, blindworms, in which the mouth is not dilatable. Origin: NL, fr. Gr, dim. Of a snake. Source: Websters Dictionary (01 Mar 1998) |
| ophidian | <zoology> One of the Ophidia; a snake or serpent. Origin: Cf. F. Ophidien. <zoology> Of or pertaining to the Ophidia; belonging to serpents. Origin: Cf. F. Ophidien. Source: Websters Dictionary (01 Mar 1998) |
| ophidiasis | Poisoning by a snake. Synonym: ophidism. Origin: G. Ophidion, dim. Of ophis, a serpent (05 Mar 2000) |
| ophidioid | <zoology> Of or pertaining to the Ophidiidae, a family of fishes which includes many slender species. One of the Ophidiidae. Origin: Ophidion. Source: Websters Dictionary (01 Mar 1998) |
| ophidion | Origin: L, fr. Gr. Little snake, fr. A serpent. <zoology> The typical genus of ophidioid fishes. Alternative forms: Ophidium Source: Websters Dictionary (01 Mar 1998) |