21-letter words containing d, i, s, f, a
- pacific standard time — See under standard time.
- pathfinder prospectus — a prospectus regarding the flotation of a new company that contains only sufficient details to test the market reaction
- peroxydisulfuric acid — persulfuric acid (def 2).
- piero della francesca — Piero della [pee-air-oh del-uh;; Italian pye-raw del-lah] /piˈɛər oʊ ˈdɛl ə;; Italian ˈpyɛ rɔ ˈdɛl lɑ/ (Show IPA), (Piero dei Franceschi) c1420–92, Italian painter.
- radius of convergence — a positive number so related to a given power series that the power series converges for every number whose absolute value is less than this particular number.
- rutherford scattering — the scattering of an alpha particle through a large angle with respect to the original direction of motion of the particle, caused by an atom (Rutherford atom) with most of the mass and all of the positive electric charge concentrated at a center or nucleus.
- safe in the knowledge — If you do something safe in the knowledge that something else is the case, you do the first thing confidently because you are sure of the second thing.
- saint-maur-des-fosses — a town in N central France, near Paris, on the Marne River.
- schema definition set — (SDS) Something in Portable Common Tool Environment.
- semantic differential — a technique for measuring the connotative meaning of concepts by having an individual rate each concept on a series of graduated scales, each scale defined by a pair of polar adjectives, as good–bad or strong–weak.
- silicon tetrafluoride — a colorless, fuming gas, SiF 4 , used chiefly in the manufacture of fluosilicic acid.
- sing a different tune — a succession of musical sounds forming an air or melody, with or without the harmony accompanying it.
- sovereign wealth fund — an investment fund created using the financial assets of a national government
- spotted alfalfa aphid — a pale yellowish aphid, Therioaphis maculata, of the southern U.S., especially west of the Mississippi River, that is marked with black spots and has fine spines on its back: a pest mainly of alfalfa and some other legumes, as clover.
- staffordshire terrier — former name of American Staffordshire terrier.
- stem-and-leaf diagram — a histogram in which the data points falling within each class interval are listed in order
- surface friction drag — the part of the drag on a body moving through a fluid that is dependent on the nature of the surface of the body
- to play second fiddle — If you play second fiddle to someone, your position is less important than theirs in something that you are doing together.
- to risk life and limb — If someone risks life and limb, they do something very dangerous that may cause them to die or be seriously injured.
- universal disk format — (storage, standard) (UDF) A CD-ROM file system standard that is required for DVD ROMs. UDF is the OSTA's replacement for the ISO 9660 file system used on CD-ROMs, but will be mostly used on DVD. DVD multimedia disks use UDF to contain MPEG audio and video streams. To read DVDs you need a DVD drive, the kernel driver for the drive, MPEG video support, and a UDF driver. DVDs containing both UDF filesystems and ISO 9660 filesystems can be read without UDF support. UDF can also be used by CD-R and CD-RW recorders in packet writing mode.
- university of iceland — (body, education) The Home of Fjolnir.