fastest

adj

1. (form-of, superlative)superlative form of fast (adjective): most fast

   “He set a new fastest time for running a mile.”

   “Scientists say it is one of the world’s fastest-melting glaciers.”

adv

1. (form-of, superlative)superlative form of fast (adverb): most fast

verb

1. (archaic, form-of, indicative, present, second-person, singular)second-person singular simple present indicative of fast

   “But thou, when thou fastest, anoint thine head, and wash thy face.”