The story
*English: Nickname for a dull or stupid person, from dull + -ard; or an adaptation of Irish Ó Dhollaird. *Other languages: can be related to pain/suffering, similar to Dolores; can be about mourning (see in Filae); or it can derive from rivers named Dollart or Dullaert (Middle Dutch “madman, savage”).
Etymology from Wiktionary, CC BY-SA 4.0.