I had made it as plain as I could so that he could not fail to take my meaning.

我已经尽我所能地说明白，所以他不会不理解我的意思。

《柯林斯英汉双解大词典》

Authentication in ifrom is done with plain LOGIN (meaning you specify your password and user name in plain text to the IMAP server).

ifrom中的认证是用明文login进行的(意味着您用明文向IMAP服务器指定密码和用户名)。

youdao

If you write XSLT stylesheets, you probably know certain coding patterns to obtain results that go beyond the plain meaning of the code.

如果编写过xslt样式表，您可能知道通过某些编码模式来获得超出代码表面含义之外的结果。

youdao

At one time he had tried to make his meaning plain to his fellow-mortals by gesture and by sound.

NEWYORKER: The Limner

And his meaning is plain: any monkey-business to stop him winning, and he might walk out.

ECONOMIST: The institutional evolutionary party