Dictionary.net

• sos'trum, n. a reward given for saving one's life, a physician's fee. [Gr., s[=o]zein, to save.]

1908 - Chambers's Twentieth Century Dictionary of the English Language
By Thomas Davidson

• A reward given to one who saves the life of another. A physician’s fee or honorarium, (F.) Honoraire.

1846 - Medical lexicon: a dictionary of medical science
By Robley Dunglison