Firm against attack; fortified by nature or art; impregnable; strong.
Of a place, characterised by business, hustle and bustle, etc.
Not running or fading when subjected to detrimental conditions such as wetness or intense light; permanent.
Causing unusual rapidity of play or action.
Steadfast, with unwavering feeling. (Now mostly in set phrases like fast friend(s).)
Able to transfer data in a short period of time.
Moving with great speed, or capable of doing so; swift, rapid.
Having a kinetic energy between 1 million and 20 million electron volts; often used to describe the energy state of free neutrons at the moment of their release by a nuclear fission or nuclear fusion reaction (i.e., before the neutrons have been slowed down by anything).
Deep or sound (of sleep); fast asleep (of people).
More sensitive to light than average.
Ahead of the correct time or schedule.
Deeply or soundly .
In a firm or secure manner, securely; in such a way as not to be moved; safe, sound .
Immediately following in place or time; close, very near .
Ahead of the correct time or schedule.
Quickly, with great speed; within a short time .
Short for "stand fast", a warning not to pass between the arrow and the target
The act or practice of fasting, religious abstinence from food
One of the fasting periods in the liturgical year
A train that calls at only some stations it passes between its origin and destination, typically just the principal stations
(academic) To cause a person or animal to abstain, especially from eating.
To reduce or limit one's nutrition intake for medical or health reasons, to diet.
To practice religious abstinence, especially from food.
Made sensitive, especially to some specific agent.