Acknowledge一词,为何OED、MWU释义中找不出left uncertain的意思?

来自MWU单词acknowledge部分,有Synonym比较,对acknowledge给出了一个在其释义中没有出现过的义项
acknowledge indicates making known to others or recognizing to one’s self what might be kept back, suppressed, or left uncertain, especially under the influence of stress, pressure, or persuasion

请问,为什么呢?毕竟OED都修订过的,既然有此意思,为何不载明,或者是有,只是我没看出来吗?

新牛津英漢詞典
acknowledge

  • accept the validity or legitimacy of.
    接受,确认…的有效性(或合法性)
    Henry acknowledged Richard as his heir.
    亨利确认理查德为他的继承人。

我这么看:因为不确定,所以才需要确认。

不确认,某些事实就会让人感觉不确定。