definition of
retention

[1] #1 retention n. [keeping, holding] the act of retaining something. wn

[2] #2 retention n. [memory, retentiveness, retentivity] the power of retaining and recalling past experience; "he had a good memory when he was younger". wn

[3] #3 retention n. [retentiveness, retentivity] the power of retaining liquid; "moisture retentivity of soil". wn