A flat (usually rectangular) container for a letter, thin package, etc..

Roget 223: covering, cover; baldachin, baldachino^†, baldaquin^†; canopy, tilt, awning, tent, marquee, tente d'abri [Fr.], umbrella, parasol, sunshade; veil (shade) 424; shield etc. (defense) 717.    roof, ceiling, thatch, tile; pantile, pentile^†; tiling, slates, slating, leads; barrack [U.S.], plafond, planchment [U.S.], tiling, shed etc. (abode) 189.    top, lid, covercle^†, door, operculum; bulkhead [U.S.].    bandage, plaster, lint, wrapping, dossil^†, finger stall.    coverlet, counterpane, sheet, quilt, tarpaulin, blanket, rug, drugget^†; housing; antimacassar, eiderdown, numdah^†, pillowcase, pillowslip^†; linoleum; saddle cloth, blanket cloth; tidy; tilpah [U.S.], apishamore [U.S.].    integument, tegument; skin, pellicle, fleece, fell, fur, leather, shagreen^†, hide; pelt, peltry^†; cordwain^†; derm^†; robe, buffalo robe [U.S.]; cuticle, scarfskin, epidermis.    clothing etc. 225; mask etc. (concealment) 530.    peel, crust, bark, rind, cortex, husk, shell, coat; eggshell, glume^†.    capsule; sheath, sheathing; pod, cod; casing, case, theca^†; elytron^†; elytrum^†; involucrum [Lat.]; wrapping, wrapper; envelope, vesicle; corn husk, corn shuck [U.S.]; dermatology, conchology; testaceology^†.    inunction^†; incrustation, superimposition, superposition, obduction^†; scale etc. (layer) 204.    [specific coverings] veneer, facing; overlay; plate, silver plate, gold plate, copper plate; engobe^†; ormolu; Sheffield plate; pavement; coating, paint; varnish etc. (resin) 216.1; plating, barrel plating, anointing etc. v.; enamel; epitaxial deposition [Eng.], vapor deposition; ground, whitewash, plaster, spackel, stucco, compo; cerement; ointment etc. (grease) 356.    ... show more

Roget 229: circumscription, limitation, inclosure; confinement etc. (restraint) 751; circumvallation^†; encincture; envelope etc. 232.    container (receptacle) 191.    ... show more

Roget 232: inclosure, envelope; case etc. (receptacle) 191; wrapper; girdle etc. 230.    pen, fold; pen fold, in fold, sheep fold; paddock, pound; corral; yard; net, seine net.    wall, hedge, hedge row; espalier; fence etc. (defense) 717; pale, paling, balustrade, rail, railing, quickset hedge, park paling, circumvallation^†, enceinte, ring fence.    barrier, barricade; gate, gateway; bent, dingle [U.S.]; door, hatch, cordon; prison etc. 752.    dike, dyke, ditch, fosse^†, moat.    ... show more

Dutch: couvert, briefomslag, envelop, enveloppe, omslag
Polish: koperta

Any wrapper or covering.

A curve that is tangent to each of a family of curves.

Dutch: briefomslag
Polish: obwiednia

A natural covering (as by a fluid).

Polish: okrywa

The maximum operating capability of a system (especially an aircraft).

The bag containing the gas in a balloon.

synonym: gasbag.

Dutch: omslag