See Also:

S (iou)



S, s.
The nineteenth letter of the modern English alphabet and the eighteenth of the ancient Roman one, derived from a Semitic (Phoenician) character, which represented a voiceless sibilant, . See also ESS noun1.
I.
The letter and its sound.
s-aorist Philology an aorist formed in certain Indo-European languages by adding s and the ending to the verbal stem.
The shape of the letter.
collar of SS: see COLLAR noun. S-bend an S-shaped bend (in a road, waste pipe, etc.). S-shaped adjective having a shape or a cross-section like the capital letter S.
b. One of the two directions of twist in spinning yarn. Usu. attrib. Cf. Z, Z 2b.
II. Symbolical uses.
Used to denote serial order; applied e.g. to the nineteenth (or often the eighteenth, I or J being omitted) group or section, sheet of a book, etc.
[Initial letter of secondary.] S wave, an earthquake wave which is a shear wave or secondary wave (cf. P wave s.v. P, P).
Physics. Denoting the quantum number of spin angular momentum of one electron (s) or an assemblage of electrons (S).
Radio. S meter, a meter that indicates the strength of a received signal.
Astronomy. [Initial letter of slow] s-process, a process believed to occur in giant stars by which heavy atomic nuclei are produced from other nuclei by a combination of neutron captures and beta decays.
Physics. S-matrix, a scattering matrix, i.e. a matrix of probability amplitudes that occurs in the expression of the initial wave functions in a scattering process in terms of all the possible final wave functions.
S-band, the range of microwave frequencies between 1550 and 5200 megahertz, used for radio communication and radar.
Chemistry. [Abbreviation of Latin sinister left] (Cap. S.) Designating (compounds having) a configuration about an asymmetric carbon atom in which the substituents, placed in order according to certain rules, form an anticlockwise sequence when viewed from a particular direction. Opp. R, R 7.
III.
Abbrevs.: (A small selection only is given here. Those all in caps. or small caps. also occur with a full stop after each letter; some of those all in caps. also occur (i) with initial cap. only, (ii) in small caps.) S. = (Anatomy & Zoology) sacral (in vertebral formulae); Society. S = Saint; (Electricity) siemens; small; (Bacteriology) smooth; South(ern); special (in S level, of the General Certificate of Education examination); strain (of virus etc.); (Particle Physics) strangeness (quantum number); (Chemistry) sulphur; (Biochemistry) Svedberg unit. s = second(s); (Physics & Chemistry) sharp (orig. designating one of the four main series (S, P, D, F) of lines in atomic spectra, now more frequently applied to electronic orbitals, states, etc., possessing zero angular momentum and total symmetry (as s-electron, s-orbital, etc.)); (in former British currency) [Latin] solidus, -di shilling(s); (Grammar) singular; son; (Physics) strange quark; succeeded.