IPA: /ˈnɪm.bəl.ɪst/
KK: /ˈnɪmblɪst/
The most quick and light in movement or action; able to move easily and quickly.
The nimblest dancer in the troupe amazed everyone with her agility.
Comparative: nimbler
Superlative: nimblest
Nimblest → It is formed from "nimble" (from Middle English "nimbl", meaning quick and light in movement) and the superlative suffix "-est" (meaning most). The word "nimblest" means the most quick and light in movement.
Think of someone who is the 'quickest' or 'most agile' — 'nimble' means quick, and '-est' indicates the highest degree.