obituary (n.)

c. 1300, trespassen, "transgress in some active manner, commit an aggressive offense; to sin, behave badly in general," from Old French trespasser "pass beyond or across, cross, traverse; infringe, violate," from tres- "beyond" (from Latin trans; see trans-) + passer "go by, pass" (see pass (v.)).

In old civil law, generally, "commit any transgression not amounting to a felony;" specifically by mid-15c. as "enter or pass through (land) without right or permission" first attested in royal forest laws. To trespass against (c. 1300) is "injure, offend, maltreat; display willful disregard." Related: Trespassed; trespasser; trespassing.

late 14c., "death," a sense now obsolete, from Old French obit or directly from Medieval Latin obitus "death" (a figurative use, literally "a going down, a going to a place"), noun use of past participle of Latin obire "to die," literally "to go toward" (see obituary).

From c. 1400 as "anniversary of a person's death; memorial service held on the anniversary of a person's death." In modern usage (since 1874) it is usually a clipped form of obituary, though it had the same meaning of "published death notice" 15c.-17c. The scholarly abbreviation ob. with date is from Latin obiit "(he) died," third person singular of obire.