v. Second-person singular simple past tense subjunctive of be (used with the pronoun "thou").
the GNU version of the Collaborative International Dictionary of English
The second person singular, indicative and subjunctive moods, imperfect tense, of the verb be. It is formed from were, with the ending -t, after the analogy of wast. Now used only in solemn or poetic style.
n. A wart.
The Century Dictionary and Cyclopedia
See was.
n. A Middle English variant of wart.
Word Usage
"The bittering hops are usually introduced to the wort say it "wert" and it is the proto-beer early in the boil and is present until the boil is over."