Meaning of RETENTION in English
re ‧ ten ‧ tion AC /rɪˈtenʃ ə n/ BrE AmE noun [uncountable]
[ Word Family: verb : ↑ retain ; noun : ↑ retention ]
[ Date: 1300-1400 ; Language: Latin ; Origin: retentio , from retinere ; ⇨ ↑ retain ]
1 . formal the act of keeping something
The UN will vote on the retention of sanctions against Iraq.
2 . technical the ability or tendency of something to hold liquid, heat etc within itself:
Many people with heart problems suffer from fluid retention.
3 . the ability to keep something in your memory:
I have a real problem with retention of information.
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012