Arthur, William (1857) An Etymological Dictionary of Family and Christian Names. New York: Sheldon, Blakeman. Public Domain.
RANKIN
As described in historical dictionaries
An Etymological Dictionary of Family and Christian Names (1857)
This name may be derived from the Danish Rank, right, upright, erect. If the name is Gaelic, it would come from Roinn, a promontory, share, or division, and Ceann, head; the head of the promontory, a name of place. Ranken, in the Dutch, signifies pranks, tricks.
Patronymica Britannica (1860)
RANKIN. I always considered this a diminutive of Randolf (see Hankin) ; but there is a tradition of descent from one John, son of a knight called Jacob de Rankine, burgomaster of Ghent, who married a daughter of the head of the house of Keith, and became progenitor of the Rankines, Ranking, Rankens, Rankings, and Rangkings of Scotland, who are i-ather numerous in the West, and on the border. The tradition is, however, dateless and vague. Inf. M. H. Rankin, Esq.
Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
Surname type: Diminutive
Origin: Celtic
Region of origin: British Isles
Country of origin: Scotland
Religion of origin: Christian
Language of origin: Gaelic