ᴹ√PERES root. “affect, disturb, alter”
A root in The Etymologies of the 1930s glossed “affect, disturb, alter” with derivatives like N. presta- “to affect, trouble, disturb” and N. pesso “it affects, concerns” (Ety/PERES; EtyAC/PERES). It had a short form ᴹ√PER (EtyAC/PERES), but in a separate entry in The Etymologies ᴹ√PER was glossed “divide in middle, halve” (Ety/PER) which doesn’t seem to be related.
References ✧ Ety/PERES; EtyAC/PERES