1. Errors of spelling, grammar, etc. that are made when typing or printing a document: Carol spotted several typos in the page that she was editing.

A typo includes errors resulting from mechanical failures or slips of the hand or finger, but essentially it shouldn't include mistakes made as a result of a lack of knowledge.

Although a typo excludes errors of ignorance, it is common to find it being used as a euphemism to describe instances of poor spelling, punctuation, or grammar.

2. Etymology: an abbreviated term for typographical, from Middle Latin typographia which came from Greek typos, "dent, impression, mark, figure, original form" + -grapheia, "writing".