Retentive

a. [Fr. rétentif, Pr. retentiu, It. retentivo, ritentitivo.] Having the power to retain; as, a retentive memory.

Nor airless dungeon, nor strong links of iron, Can be retentive to the strength of spirit. Shak.

That which retains or confines; a restraint. [Obs.] Bp. Hall.