ORPAH (ôr'pa, Heb. ‘orpâh, neck, i.e. stubbornness). A Moabite woman whom Kilion, son of Elimelech and Naomi, married. She loved her mother-in-law, but kissed her good-by and remained in Moab, while Ruth, Naomi’s other daughter-in-law, stayed with her (Ruth.1.4, Ruth.1.14; Ruth.4.9-Ruth.4.10).
ORPAH ôr’ pə (עָרְפָּ֔ה, meaning uncertain; neck, gazelle, youthful have been suggested). A Moabitess who married Chilion, one of two sons of Elimelech and Naomi, after the family had migrated to Moab from Judah in time of famine during the period of the Judges (Ruth 1:1-4). Ruth married the other son, Mahlon (1:4; 4:10). After the death of her husband and two sons, Naomi departed for her homeland accompanied by her two widowed daughters-in-law. Upon urging by Naomi, Orpah returned to her own people and god, Chemosh, (1:15; Judg 11:24), in contrast to Ruth who would not leave Naomi.
International Standard Bible Encyclopedia (1915)
A Moabitess, wife of Mahlon, son of Elimelech and Naomi. Unlike her sister Ru she returned to her own people after escorting Naomi on her way to Judah (Ru 1:4 ). Her name is supposed to be derived from the Hebrew word for "neck" (`oreph), and so to mean "stiff-necked" because of her turning-back from following her mother-in-law; others take it to mean "gazelle."