21-letter words containing a, p, o, n, e, u
- rectangular hyperbola — a hyperbola with perpendicular asymptotes
- residual unemployment — the unemployment that remains in periods of full employment, as a result of those mentally, physically, or emotionally unfit to work
- saponification number — the number of milligrams of potassium hydroxide required to saponify one gram of a given ester, especially a glyceride.
- sequoia national park — a national park in central California: giant sequoia trees. 604 sq. mi. (1565 sq. km).
- simple actor language — (language) (SAL) A minimal actor language, used for teaching in:
- single spanish burton — a tackle having a runner as well as the fall supporting the load, giving a mechanical advantage of three, neglecting friction.
- sinusoidal projection — an equal-area projection in which parallels are straight lines spaced at regular intervals, the central meridian is a straight line one-half the length of the equator, and the other meridians are curves symmetrical to the central meridian.
- social inquiry report — (in Britain) a report on a person and his or her circumstances, which may be required by a court before sentencing and is made by a probation officer or a social worker from a local authority social services department
- south pacific current — an ocean current that flows E in the South Pacific Ocean parallel to the Antarctic Circumpolar Current.
- spin angular momentum — to make (yarn) by drawing out, twisting, and winding fibers: Pioneer women spun yarn on spinning wheels.
- stop loss reinsurance — Stop loss reinsurance is a form of reinsurance under which the reinsurer pays the cedant's losses in any year over a particular percentage of the earned premium.
- student participation — the extent to which students participate or involve themselves in a class, course, etc
- subliminal perception — perception of or reaction to a stimulus that occurs without awareness or consciousness
- sun protection factor — SPF.
- supergranulation cell — one of a number of large convection cells in the photosphere and chromosphere of the sun, each having a diameter of 10,000–20,000 miles (16,000–32,000 km) and lasting longer than a day.
- surface of projection — the surface upon which an image or a set of points is projected.
- symphonie fantastique — a programmatic symphony (1830–31) in five movements by Hector Berlioz.
- temperature inversion — inversion (def 12).
- tenure track position — a position or office that carries with it the opportunity to eventually obtain tenure or the right to permanent employment
- therapeutic community — a group-based form of therapy for mental disorders, sometimes residential
- turn up one's nose at — to sneer at; scorn
- ulster unionist party — a Northern Irish political party advocating the maintenance of union with the UK
- up close and personal — face to face, intimately
- up hill and down dale — strenuously and persistently
- whip-and-tongue graft — a graft prepared by cutting both the scion and the stock in a sloping direction and inserting a tongue in the scion into a slit in the stock.
- xeroderma pigmentosum — a rare inherited disease characterized by sensitivity to ultraviolet light, exposure resulting in lesions and tumors of the skin and eyes.