retention /rɪˈtɛnʃən/ noun Learner's definition of RETENTION
[noncount] formal
1
a : the act of keeping someone or something保留;留住;保持 b : the act of keeping extra liquid, heat, etc., inside the body(热量的)阻滞;(液体的)潴留 2
: the ability to keep something保持力;持续力 3
: the ability to remember things easily or for a long time记性;记忆力