From haphak; a perversity or fraud -- (very) froward(-ness, thing), perverse thing.
see HEBREW haphak
H8420. tav
תָּו noun masculine mark; — absolute ׳ת, mark on forehead, sign of exemption from judgment Ezekiel 9:4, 6 suffix תָּוֺוי Job 31:35 = my (written) mark (in attestation).