This is the 566th most frequent Icelandic word.
flest
"Flest" means "most" in English.
The word 'flestir' here signifies 'most' referring to the majority within a group of people.
Flestir nemendur mættu á tíma.
Most students attended the class.
The word 'flest' here is used neutrally to refer to the majority of aspects or elements in an unspecified group.
Það er flest sem þú skilur í tungumálakennslu ef þú æfir reglulega.
You understand most in language teaching if you practice regularly.
In this sentence, 'flestar' is the feminine plural form of 'flest,' used to quantify books which are considered feminine nouns in Icelandic.