INSCRUTABLE

[in.scru.ta.ble] adj [ME, fr. LL inscrutabilis, fr. L in- + scrutari to search--more at scrutiny] (15c): not readily investigated, interpreted, or understood: mysterious -- in.scru.ta.bil.i.ty n -- in.scru.ta.ble.ness n -- in.scru.ta.bly adv