An Etymological Dictionary of Astronomy and Astrophysics

The act of dying; the end of life.

Etymology (EN): M.E. deeth, O.E. deað (cf. O.S. doth, O.Fris. dath, Du. dood, O.H.G. tod, Ger. Tod, O.N. dauði, Dan. død, Swed. död, Goth. dauþas “death”), from dheu- “to die” + -thuz “-th;”

Etymology (PE): Marg “death,” from Mid.Pers. marg “death;” Av. mahrka- “death,” mərəxš- “ruin;” related to Mod.Pers. mordan (present stem mir-) “to die;” Mid.Pers. murdan
“to die;” O.Pers. mrt- “to die,” amriyta “dies,” martiya- “(mortal) man” (Mod.Pers. mard “man”); Av. mərəta- “died;” cf. Skt. mar- “to die,” mrti- “death,” marc- “to damage, hurt, injure;” PIE base *mor-/*mr- “to die.” Cognates in other IE languages: Gk. emorten “died,” ambrotos “immortal;”
L. morior “I die,” mortuus “dead” (Fr. mourir “to die,” mort “dead”); Arm. merani- “to die;” O.C.S. mrutvu “dead;” O.Ir. marb; Welsh marw “died;” O.E. morþ “murder;” Lith. mirtis.