retention
noun /rɪˈtenʃn/
  /rɪˈtenʃn/
[uncountable] (formal)- the action of keeping something rather than losing it or stopping it
- The company needs to improve its training and retention of staff.
 
 - the action of keeping liquid, heat, etc. inside something rather than letting it escape
- Eating too much salt can cause fluid retention.
 - the importance of energy conservation and heat retention
 
 - the ability to remember things
- Visual material aids the retention of information.
 
 see also retain 
Word Originlate Middle English (denoting the power to retain something): from Old French, from Latin retentio(n-), from retinere ‘hold back’, from re- ‘back’ + tenere ‘hold’.