This is the 221st most frequent Indonesian word.
cepat
Fast.
Here, 'cepat' is used as an adverb to describe the manner of running.
Dia berlari sangat cepat dibandingkan teman lainnya.
He runs very fast compared to other friends.
In this sentence, 'cepat' acts as an adjective describing the noun 'answer'.
Kami membutuhkan jawaban yang cepat untuk masalah ini.
We need a prompt answer for this issue.
'Kecepatan', derived from 'cepat', is used as a noun meaning 'speed'.