I’m guessing it means, like smite, to “strike down” or “defeat in battle”. It’s probably an archaic version. I couldn’t find any meaningful definition. Sorry.
I think in old english, -eth is added to the verb the way we add an s to make the verb agree with the subject. Like in OE. “He smiteh the lion” would be in ME. “He smites the lion”. Definitly present tense not past tense.