Retentive

1. (a.) Having power to retain; as, a retentive memory.

2. (n.) That which retains or confines; a restraint.

Thesaurus Entries

adhering, adhesion, agglutinate, bond, cleaving, cling, coherence, coherent, cohering, cohesion, cohesive, grasping, gripping, holding, holding together, keeping, retentive, sticking, stuck, tenacious