IPA: /ˈpjʊrɪst/
KK: /pjʊrɪst/
Having the highest level of cleanliness or quality, free from any contamination or imperfections.
This is the purest water I have ever tasted.
Comparative: purer
Superlative: purest
Purest → It is formed from "pure" (from Latin *purus*, meaning clean or untainted) and "-est" (a suffix used to form the superlative degree). The word "purest" means the highest degree of purity or cleanliness.
Think of 'pure' meaning clean or untainted, and remember that 'purest' refers to the highest level of that cleanliness.