"Wert recumbent" is a phrase often used in historical texts to describe someone who was lying down. The unusual spelling of "wert" can be explained through IPA phonetic transcription: /wɜrt/. This shows that "wert" is pronounced with a schwa sound (represented by ə) followed by the consonant cluster "rt." It can be confusing for modern readers who are used to seeing the word spelled as "were," but it is simply an archaic spelling that was commonly used in early English.
There seems to be a confusion in your question. "Wert recumbent" is not a word or a phrase with an established meaning or etymology. "Wert" is an archaic form of the verb "be" in the second person singular past tense (similar to "were"), and "recumbent" means lying down or reclining. However, "wert recumbent" does not form a coherent phrase or have a clear meaning.