Use slip of the pen in a sentence | slip of the pen definition

Use "slip of the pen" in a sentence

1. In all the excitement the Registrar, Mrs Molly Croll, suffered a slip of the pen.

2. Allowing for the unfortunate slip of the pen by which "Batrachians" are substituted for "fresh-water polyps," how can we fail to admire the severity of the scientific method employed in reaching these interesting …