godan verb (-u), transitive verb
misspeak; say incorrectly; make a slip of the tongue
Used when one accidentally says the wrong thing, uses the wrong word, or makes a verbal mistake.
緊張して、名前を言い損なってしまった。
I was nervous and ended up saying the name wrong.
彼はよく言葉を
He often misspeaks.
godan verb (-u), transitive verb
forget to say; miss the chance to say
Used when one fails to say something important, often due to timing or forgetfulness.
大事なことを言い損なって、後で後悔した。
I forgot to say something important and regretted it later.
彼に感謝の言葉を言い損なった。
I missed the chance to say thank you to him.