Rapidly vs. Fast

With speed; in a rapid manner.

Example: ‘She packed her case rapidly and hurried out.’;

In a rapid manner.

with rapid movements;

Example: ‘he works quickly’;

(dated) Firmly or securely fixed in place; stable.

Example: ‘That rope is dangerously loose. Make it fast!’;

Firm against attack; fortified by nature or art; impregnable; strong.

(of people) Steadfast, with unwavering feeling. (Now mostly in set phrases like fast friend(s).)

Moving with great speed, or capable of doing so; swift, rapid.

Example: ‘I am going to buy a fast car.’;

Causing unusual rapidity of play or action.

Example: ‘a fast racket, or tennis court; a fast track; a fast billiard table; a fast dance floor’;

Able to transfer data in a short period of time.

Deep or sound (of sleep); fast asleep (of people).

(of dyes or colours) Not running or fading when subjected to detrimental conditions such as wetness or intense light; permanent.

Example: ‘All the washing has come out pink. That red tee-shirt was not fast.’;

(obsolete) Tenacious; retentive.

(dated) Having an extravagant lifestyle or immoral habits.

Example: ‘a fast woman’;

Ahead of the correct time or schedule.

Example: ‘There must be something wrong with the hall clock. It is always fast.’;

(of photographic film) More sensitive to light than average.

In a firm or secure manner, securely; in such a way as not to be moved; safe, sound .

Example: ‘Hold this rope as fast as you can.’;

(of sleeping) Deeply or soundly .

Example: ‘He is fast asleep.’;

Immediately following in place or time; close, very near .

Example: ‘The horsemen came fast on our heels.’;

Quickly, with great speed; within a short time .

Example: ‘Do it as fast as you can.’;

Ahead of the correct time or schedule.

Example: ‘I think my watch is running fast.’;

A train that calls at only some stations it passes between its origin and destination, typically just the principal stations

The act or practice of abstaining from food or of eating very little food.

The period of time during which one abstains from or eats very little food.

Example: ‘Lent and Ramadan are fasts of two religions.’;

(archery) Short for "stand fast", a warning not to pass between the arrow and the target

(intransitive) To restrict one’s personal consumption, generally of food, but sometimes other things, in various manners (totally, temporally, by avoiding particular items), often for religious or medical reasons.

Example: ‘Muslims fast during Ramadan and Catholics during Lent.’;

To abstain from food; to omit to take nourishment in whole or in part; to go hungry.

Example: ‘Fasting he went to sleep, and fasting waked.’;

To practice abstinence as a religious exercise or duty; to abstain from food voluntarily for a time, for the mortification of the body or appetites, or as a token of grief, or humiliation and penitence.

Example: ‘Thou didst fast and weep for the child.’;

Abstinence from food; omission to take nourishment.

Example: ‘Surfeit is the father of much fast.’;

Voluntary abstinence from food, for a space of time, as a spiritual discipline, or as a token of religious humiliation.

A time of fasting, whether a day, week, or longer time; a period of abstinence from food or certain kinds of food; as, an annual fast.

That which fastens or holds; especially, (Naut.) a mooring rope, hawser, or chain; - called, according to its position, a bow, head, quarter, breast, or stern fast; also, a post on a pier around which hawsers are passed in mooring.

Firmly fixed; closely adhering; made firm; not loose, unstable, or easily moved; immovable; as, to make fast the door.

Example: ‘There is an order that keeps things fast.’;

Firm against attack; fortified by nature or art; impregnable; strong.

Example: ‘Outlaws . . . lurking in woods and fast places.’;

Firm in adherence; steadfast; not easily separated or alienated; faithful; as, a fast friend.

Permanent; not liable to fade by exposure to air or by washing; durable; lasting; as, fast colors.

Tenacious; retentive.

Example: ‘Roses, damask and red, are fast flowers of their smells.’;

Not easily disturbed or broken; deep; sound.

Example: ‘All this while in a most fast sleep.’;

Moving rapidly; quick in mition; rapid; swift; as, a fast horse.

Given to pleasure seeking; disregardful of restraint; reckless; wild; dissipated; dissolute; as, a fast man; a fast liver.

In such a condition, as to resilience, etc., as to make possible unusual rapidity of play or action; as, a fast racket, or tennis court; a fast track; a fast billiard table, etc.

In a fast, fixed, or firmly established manner; fixedly; firmly; immovably.

Example: ‘We will bind thee fast.’;

In a fast or rapid manner; quickly; swiftly; extravagantly; wildly; as, to run fast; to live fast.

Example: ‘He, after Eve seduced, unminded slunkInto the wood fast by.’; ‘Fast by the throne obsequious Fame resides.’;

abstaining from food

abstain from certain foods, as for religious or medical reasons;

Example: ‘Catholics sometimes fast during Lent’;

abstain from eating;

Example: ‘Before the medical exam, you must fast’;

acting or moving or capable of acting or moving quickly;

Example: ‘fast film’; ‘on the fast track in school’; ‘set a fast pace’; ‘a fast car’;

(used of timepieces) indicating a time ahead of or later than the correct time;

Example: ‘my watch is fast’;

at a rapid tempo;

Example: ‘the band played a fast fox trot’;

(of surfaces) conducive to rapid speeds;

Example: ‘a fast road’; ‘grass courts are faster than clay’;

firmly fastened or secured against opening;

Example: ‘windows and doors were all fast’; ‘a locked closet’; ‘left the house properly secured’;

resistant to destruction or fading;

Example: ‘fast colors’;

unrestrained by convention or morality;

Example: ‘Congreve draws a debauched aristocratic society’; ‘deplorably dissipated and degraded’; ‘riotous living’; ‘fast women’;

hurried and brief;

Example: ‘paid a flying visit’; ‘took a flying glance at the book’; ‘a quick inspection’; ‘a fast visit’;

securely fixed in place;

Example: ‘the post was still firm after being hit by the car’;

unwavering in devotion to friend or vow or cause;

Example: ‘a firm ally’; ‘loyal supporters’; ‘the true-hearted soldier...of Tippecanoe’; ‘fast friends’;

quickly or rapidly (often used as a combining form);

Example: ‘how fast can he get here?’; ‘ran as fast as he could’; ‘needs medical help fast’; ‘fast-running rivers’; ‘fast-breaking news’; ‘fast-opening (or fast-closing) shutters’;

firmly or tightly;

Example: ‘held fast to the rope’; ‘her foot was stuck fast’; ‘held tight’;