a mistake in printed matter resulting from mechanical failures of some kind
"The editor had to reprint the entire brochure because a faulty printing press caused smudged ink that looked like missing letters on every page."
A typographical error.
"The old newspaper editor hired a skilled typo to manually set the type for his morning edition before the presses could even turn over."
A compositor; a typographer.
To make a typographical error.
"I accidentally sent him an email full of typos because I was typing too fast on my phone."