From BiblePortal Wikipedia

Hastings' Dictionary of the Bible [1]

Darling .   Psalms 22:20 ‘Deliver my darling from the power of the dog’;   Psalms 35:17 ‘rescue my soul from their destructions, my darling from the lions.’ The Heb. word ( yâhîdh ) means an only son. In the Psalms it is used poetically of the psalmist’s own life, as his unique and priceless possession.

Webster's Dictionary [2]

(1): ( a.) Dearly beloved; regarded with especial kindness and tenderness; favorite.

(2): ( n.) One dearly beloved; a favorite.

King James Dictionary [3]

D'ARLING, a. Dearly beloved favorite regarded with great kindness and tenderness as a darling child a darling science.

D'ARLING, n. One much beloved a favorite as, that son was the darling of his father.

Easton's Bible Dictionary [4]

 Psalm 22:20 35:17

International Standard Bible Encyclopedia [5]

dar´ling ( יחיד , yāḥı̄dh , "only," the King James Version margin, "only one"; the American Revised Version, margin, " dear life"): Used poetically for the life or soul (  Psalm 22:20;  Psalm 35:17 ).

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [6]

( יָחַיד , Yachid' , only, hence beloved) stands ( Psalms 22:21;  Psalms 35:17) for life (as a thing not to be replaced); hence Self (like נֶפֶשׁ , soul; comp. "dear me").

The Nuttall Encyclopedia [7]

A tributary of the Murray River, in Australia, now stagnant, now flooded.