Second person singular, present tense of read(verb)
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Use "readest" in a sentence
"Thy presence, perhaps, thou hardened wretch, might have made us ashamed of a weakness which perhaps thou wilt deride me in particular for, when thou readest this! — —"
"All thy phlegm I know will be roused into vengeance when thou readest it."
"And Philip ran thither to him, and heard him read the prophet Esaias, and said, Understandest thou what thou readest?"