former adverbial cousin to fast (adj.), from Old English fæstlic “firm, fixed, steadfast, resolute;” obsolete in 19c., simple fast taking its place.
[fast-moo-ving, fahst-] /ˈfæstˈmu vɪŋ, ˈfɑst-/ adjective 1. moving or capable of moving at high speed. 2. (of a novel, play, or the like) having sustained action and interest with events following one another rapidly; lively in plot.
[fast-nis, fahst-] /ˈfæst nɪs, ˈfɑst-/ noun 1. a secure or fortified place; stronghold: a mountain fastness. 2. the state of being fixed or firm: the fastness of democratic institutions. 3. the state of being rapid. /ˈfɑːstnɪs/ noun 1. a stronghold; fortress 2. the state or quality of being firm or secure 3. the ability of […]
noun, Judaism. 1. . [tah-nit es-ter, -nis; Sephardic Hebrew tah-ah-neet es-ter; Ashkenazic Hebrew tah-ah-nis es-tuh r] /ˈtɑˌnɪt ˈɛs tər, -nɪs; Sephardic Hebrew ˌtɑ ɑˈnit ɛsˈtɛr; Ashkenazic Hebrew ˈtɑ ɑ nɪs ˈɛs tər/ noun 1. a Jewish fast day observed on the 13th day of the month of Adar in memory of Esther’s fast of three […]
- Fast neutron
noun 1. (physics) fast neutron A neutron that is not in thermal equilibrium with the surrounding medium, especially one produced by fission. Compare slow neutron. See also fast-breeder reactor.