adj. & adv.
1 rapid, quick-moving.
2 capable of high speed (a fast car).
3 enabling or causing or intended for high speed (a fast road; fast lane).
4 (of a clock etc.) showing a time ahead of the correct time.
5 (of a pitch or ground etc. in a sport) likely to make the ball bounce or run quickly.
6 a (of a photographic film) needing only a short exposure. b (of a lens) having a large aperture.
7 a firmly fixed or attached. b secure; firmly established (a fast friendship).
8 (of a colour) not fading in light or when washed.
9 (of a person) immoral, dissipated.
1 quickly; in quick succession.
2 firmly, fixedly, tightly, securely (stand fast; eyes fast shut).
3 soundly, completely (fast asleep).
Phrases and idioms:
fast breeder (or fast breeder reactor) a reactor using fast neutrons to produce the same fissile material as it uses. fast buck see BUCK(2). fast food food that can be prepared and served quickly and easily, esp. in a snack bar or restaurant. fast neutron a neutron with high kinetic energy, esp. not slowed by a moderator etc. fast reactor a nuclear reactor using mainly fast neutrons. fast-talk US colloq. persuade by rapid or deceitful talk. fast-wind wind (magnetic tape) rapidly backwards or forwards. fast worker colloq. a person who achieves quick results, esp. in love affairs. pull a fast one colloq. try to deceive or gain an unfair advantage.
Etymology: OE faeligst f. Gmc
v. & n.
—v.intr. abstain from all or some kinds of food or drink, esp. as a religious observance.
—n. an act or period of fasting.
Etymology: ON fasta f. Gmc (as FAST(1))
Useful english dictionary. 2012.