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 (other than preterite-presents).

Used to form the second-person singular past indicative of weak verbs; see -edest

Used to form the second-person singular past indicative of strong verbs

↑ “-est, suf.(3).”, in MED Online, Ann Arbor, Mich.: University of Michigan, 2007.

↑ Sandved, Arthur (1985), “10. Inflection”, in Introduction to Chaucerian English (Chaucer Studies; 11), Part II: Morphology, Cambridge: D. S. Brewer, →ISBN, →OCLC, page 83.

↑ Dobson, E[ric] J. (1957), English pronunciation 1500-1700‎, second edition, volume II: Phonology, Oxford: Clarendon Press, published 1968, →OCLC, § 315, page 886.

↑ Brunner, Karl (1963), “III: Inflexions and their Use”, in Grahame Johnson, transl., An Outline of Middle English Grammar‎, Oxford: Basil Blackwell, translation of Abriss der mittelenglischen Grammatik (in German), →ISBN, →OCLC, § 68, page 70; reprinted 1965.

Used to form the superlative degree of adjectives; more, -er.

Used to form the superlative degree of adverbs; more, -er.

suffix forming feminine nouns, originally from verbs

alternative form of -ost (“used to form superlative adjectives and adverbs”)

Forms the second-person singular of class I weak verbs

verb suffix for the second-person singular preterite

Source: wiktionary.org