fast

Able to move or do something in a short time.

• This is a fast train.
• We need a faster internet connection.
• Is your new computer fast enough?

Similar words: quick, rapid, speedy

Opposites: slow

Common phrases: a fast car, fast internet, a fast runner, fast trains

Remaining close and loyal to someone, especially as a friend.

• They soon became fast friends.
• She remained his fast friend throughout the difficult years.
• The two neighbors have been fast friends since childhood.

Similar words: loyal, faithful, steadfast

Common phrases: fast friends, a fast friend

A period when someone chooses not to eat, often for religious or health reasons.

• Her fast lasted one day.
• They broke their fast at sunset.
• The test requires an overnight fast.

Common phrases: break a fast, a religious fast, an overnight fast

At a high speed or in a short time.

• He runs very fast.
• You drove too fast on that narrow road.
• How fast can you type?

Similar words: quickly, rapidly

Opposites: slowly

Common phrases: run fast, work fast, too fast

Firmly or securely, so that someone or something cannot move or come loose.

• Hold fast to the rope.
• The boat was stuck fast in the mud.
• She tied the gate fast before the storm.

Similar words: firmly, securely, tightly

Opposites: loosely

Common phrases: hold fast, stuck fast, tied fast

To choose not to eat for a period, often for religious or health reasons.

• They fast during Ramadan.
• I fasted before my blood test.
• How long do you need to fast?

How to use it: fast for a period (She fasted for twelve hours before the test.); fast during something (Many Muslims fast during Ramadan.)

Common phrases: fast for something, fast during ramadan, fast before something

To make a person or animal go without food for a period.

• The vet fasted the dog overnight.
• The team fasted the animals before the procedure.
• Patients were fasted for several hours before surgery.

Common phrases: fast an animal, fast a patient