Feminine of a derivative of proistemi; a patroness, i.e. Assistant -- succourer.
see GREEK proistemi
a. properly, a woman set over others.
b. a female guardian, protectress, patroness, caring for the affairs of others and aiding them with her resources (A. V. succourer): Romans 16:2; cf. Passow on the word and under προστάτης at the end; (Schürer, Die Gemeindeverfassung der Juden in Rom, as above with (Leip. 1879), p. 31; Heinrici, Die Christengemeinde Korinths, in Hilgenfeld's Zeitschr. for 1876, p. 517f).