late 13c., with -ful, from Middle English dole "emotion of grief, sorrow, lamentation, mourning" (early 13c., now archaic), from Old French doel (Modern French deuil), from Late Latin dolus "grief," from Latin dolere "suffer, grieve," which is of uncertain origin. De Vaan explains it as from PIE *dolh-eie- "to split" (source also of Middle Welsh e-thyl "chooses"), a causative verb from root *delh- "to chop," "under the assumption than 'pain' was expressed by the feeling of 'being torn apart'." Related: Dolefully; dolefulness.
