What is the meaning of -est?

Used to form the superlative of adjectives and adverbs.

Used to form the second-person singular present tense and past tense of verbs. (if thou is the subject; not used with you)

Used to form the second person plural preterite indicative of second conjugation verbs

Added to a word to form an adverb.

Used to form the second-person singular present indicative of verbs.

suffix forming feminine nouns, originally from verbs

verb suffix for the second-person singular preterite

Source: wiktionary.org