The Collaborative International Dictionary of English v.0.48:

Subminister \Sub*min"is*ter\, v. t. [L. subministrare,
   subministratum. See Sub-, and Ministre, v. t.]
   To supply; to afford. [Obs.] --Sir M. Hale.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Subminister \Sub*min"is*ter\, v. i.
   To be subservient; to be useful. [Obs.] "Our passions . . .
   subminister to the best and worst purposes." --L'EStrange.
   [1913 Webster]