sēd-

Meaning

1. morphemePrevocalic form of sē-
   sēd- + itiō → sēditiō

Origins

*s(w)ēd, the ablative singular of Proto-Indo-European *swé (“self”) lengthened under phrasal stress. Original form preserving the inherited /d/, which has been reinterpreted as hiatus-filler, but lost otherwise in all cases of long vowel preceding final /d/, such as other ablatives. Doublet of sē as well as sed, where the vowel shortened (or never lengthened).