Etymology From Middle English dere, from Old English dæru, daru (“injury, hurt, harm, damage, calamity; loss, deprivation”), from Proto-West Germanic *daru, from Proto-Germanic *darō (“damage, injury”), from Proto-Indo-European *dʰórh₃-eh₂, from *dʰerh₃- (“to leap, spring”). Cognate with Middle Dutch dare, dere, Low German dere, Old High German tara, Avestan 𐬛𐬁𐬭𐬁 (dārā), Sanskrit धारा (dhā́rā).
Etymology From Middle English deren, from Old English derian (“to damage, injure, hurt, harm”), from Proto-West Germanic *darjan (“to injure, harm”), from Proto-Indo-European *dʰerh₃- (“to leap, spring”). Cognate with Saterland Frisian dera (“to injure, damage”), West Frisian deare, derre (“to harm, injure”), Dutch deren (“to injure, damage, scathe”), Middle High German tern (“to injure”). Related to dart.