fosterage

I was always a dependent thing, wanting fosterage and support.

From The Life and Letters of Mary Wollstonecraft Shelley, Volume II (of 2) by Florence A. Thomas Marshall

This conjecture is corroborated by the numerous instances in history and in story of fosterage affection proving, when tested, stronger than the natural affection of relatives by birth.

From The Glories of Ireland by P. J. Lennox

There was fosterage for affection, for payment and for a literary education.

From Encyclopaedia Britannica, 11th Edition, Volume 4, Slice 4 "Bradford, William" to "Brequigny, Louis" by Various

Rejoined Aslan, "O Commander of the Faithful, he is no father of mine, save by right of fosterage; my father was none other than Ala al-Din Abu al Shamat."

From The Book of the Thousand Nights and a Night — Volume 04 by Sir Richard Francis Burton

The terms of fosterage seem to vary in different islands. 

From Journey to the Western Islands of Scotland by Samuel Johnson