distention (n.)

also distension, "act of distending; state of being distended," early 15c., distensioun, from Latin distensionem/distentionem (nominative distensio/distentio), noun of action from past participle stem of distendere "to swell or stretch out, extend," from dis- "apart" (see dis-) + tendere "to stretch," from PIE root *ten- "to stretch."