Heard spelling

theerse

Spelled thyrse. two changes at once

Does thyrse have a long vowel?

No. It rhymes with verse and nurse, not with fierce.

Theerse writes a long ee where the word has a short vowel coloured by the r behind it. The confusion comes from the y, which does say ee in plenty of Greek loans, though mostly at the ends of words, as in anatomy or symmetry.

Say

THURSS, rhyming with verse

Letters

T-H-Y-R-S-E