Meaning of -EST in English

-EST

-est /əst, ɪst/ AmE suffix

[ Language: Old English ; Origin: -est , -ost ]

forms the ↑ superlative of many short adjectives and adverbs:

cold, colder, coldest

early, earlier, earliest

⇨ ↑ -er 1

Longman Dictionary of Contemporary English.      Longman - Словарь современного английского языка.