The following thirteen words have a special property common to all of them (though they're not the only words with this property):
SADIST, THOROUGHFARE, HYMN, POISED, YURT, THIRTY-SEVEN, STREWN, VERTICALITY, INERTIA, BALDERDASH, HIGHFLYING, REWARDING, OPINIONATED
Firstly, what is this property? Secondly, which two words in the list have the property more than the other eleven?
the idea behind this puzzle also appears in another puzzle posted in the last few days, although that one is less enigmatic.