17-letter words containing a, f, r, c, y
- natural frequency — the frequency at which a system vibrates when set in free vibration
- odour of sanctity — sanctimoniousness
- off-year election — (in the US) an election held in a year when a presidential election does not take place
- peacock butterfly — a European nymphalid butterfly, Inachis io, having reddish-brown wings each marked with a purple eyespot
- phenylformic acid — benzoic acid.
- proficiency badge — an insignia or device granted by the Girl Scouts and worn especially on a uniform to indicate special achievement.
- pyrosulfuric acid — a strong, crystalline acid, H2S2O7, prepared commercially as a heavy, oily, fuming liquid: used in making explosives and dyes, as a sulfating agent, etc.
- reference library — A reference library is a library that contains books which you can look at in the library itself but which you cannot borrow.
- refractory period — a short period after a nerve or muscle cell fires during which the cell cannot respond to additional stimulation.
- safety precaution — a precaution that is taken in order to ensure that something is safe and not dangerous
- san francisco bay — a bay in W California: the harbor of San Francisco; connected with the Pacific by the Golden Gate strait. 50 miles (80 km) long; 3–12 miles (5–19 km) wide.
- sister of charity — a member of one of several congregations of sisters founded in 1634 by St. Vincent de Paul.
- spatial frequency — the measure of fine detail in an optical image in terms of cycles per millimetre
- the factory floor — all the workers in a factory
- to show your face — If you show your face somewhere, you go there and see people, although you are not welcome, are rather unwilling to go, or have not been there for some time.
- tyrant flycatcher — flycatcher (def 2).
- unconformity trap — An unconformity trap is a hydrocarbon trap where the closure is made by an unconformity (= a formation of rock layers which represents a gap in the geological record).
- unify corporation — (company) Developers of the Unify relational database. At one time, before Sybase, they were a competitor of Oracle, et al.
- walleye surfperch — a common black and silvery surfperch (Hyperprosopon argenteum) found off the coast of California
- willow flycatcher — a North American flycatcher, Empidonax alnorum, of alder thickets and other moist areas, that has greenish-brown upper parts and whitish underparts and is almost indistinguishable except by voice from E. traillii (willow flycatcher)
- x-ray diffraction — diffraction of x-rays by the regularly spaced atoms of a crystal, useful for determining the arrangement of the atoms.
- year of confusion — (in ancient Rome) the year of 445 days preceding the introduction, in 46 b.c., of the Julian calendar: lengthened to compensate for the cumulative errors of the Roman calendar.