Easton's Bible Dictionary (1897)
Ps. 22:20; 35:17) means an “only one.”
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
DARL'ING. The word occurs in Ps 22:20 and Ps 35:17 as the translation of a Hebrew word which correctly means "my only one," as it is applied to "something which exists singly and cannot be replaced if lost, as an only son. Gen 22:2, or daughter." Jud 11:34.