The Dutch word for fast is
snel

Dutch Definition

snel	©
1. adj. fast, quick, rapid
2. v. first-person singular present indicative of snellen
3. v. imperative of snellen

vasten
1. v. to fast
2. n-m. fast (period of time when one abstains from or eats very little food)

vlug
1. adj. quick, fast

rap
1. adj. quick, fast
Kom eens heel rap hier! - Get over here real fast!
2. n-m. rap music

kwiek
1. adj. lively, quick

gezwind
1. adj. (dated) rapid, brisk

vast
1. adj. firm, fast, tight
2. adj. fixed, not moving or changing
Kunnen we de vaste lasten dragen? - Can we sustain the fixed costs?
3. adj. stuck, unable to get out
Haar hand zat vast in het gat. - Her hand was stuck in the hole.
4. adj. (chemistry) in the solid state
Bij kamertemperatuur is het een vaste stof. - It is a solid substance at room temperature.
5. adj. (botany) perennial
Hij heeft een aantal vaste planten gepoot. - He has planted a few perennial plants.
6. adj. (of a telephone) using a landline
Is er een vaste verbinding? - Is there a landline connection?
7. adv. (obsolete) almost; about; close to
8. adv. surely, certainly
9. adv. (informal, sarcastically) sure, yeah, right
Mijn hond at mijn huiswerk. — Ja, vast! - My dog ate my homework. — Yeah, right!
10. v. first-person singular present indicative of vasten
11. v. second-person singular present indicative of vasten
12. v. third-person singular present indicative of vasten
13. v. imperative of vasten