/rɪ'tenʃn; rɪ`tɛnʃən/
n [U, sing] (fml 文)1 possession or use of sth 具有; 具备; 享有; 享用
*retention of one's rights, privileges, etc 权利、特权等的享有
* the full retention of one's (mental) faculties （心智）能力的健全.
2 ability to remember things 记忆力; 记性
*her limited/extraordinary powers of retention 她那有限的[非凡的]记忆力
* show an amazing retention of facts, details, childhood impressions, etc 显示出对事实、细节、儿时情景等的惊人记忆力.
3 action of holding sth in position or containing it 挡住; 拦阻; 保持; 保留; 容纳
*the retention of flood waters, crowds 拦住洪水、人群
* suffer from retention of urine, ie failure to pass it out from the bladder 患闭尿症（不能排尿）.

n[U]
[Date: 1300-1400; Language: Latin;Origin: retentio, from retinere; RETAIN]
formal the act of keeping something
retention of
　The UN will vote on the retention of sanctions against Iraq.
technical the ability or tendency of something to hold liquid, heat etc within itself
　Many people with heart problems suffer from fluid retention.
the ability to keep something in your memory
　I have a real problem with retention of information.