Having power to retain / (slang, apocope) anal-retentive

(obsolete) That which retains or confines; a restraint.

In a retentive manner.

the state of being retentive

plural of retentive

The act of retaining or something retained / The act or power of remembering things / A memory; what is retained in the mind / (medicine) The involuntary withholding of urine and faeces

That which is retained, especially by a filter or porous membrane.

plural of retention

plural of retentate

the ability to retain, potential for retention / (sciences) the capacity to retain magnetism after the magnetizing action