| Definition -
The name for the ^ symbol when it
is used as a proofreading mark to show the place where either a punctuation mark or some text should be inserted in a document.
1. You put it below the text line for line-level punctuation marks (e.g. the period) and above the text line for raised marks (e.g. the apostrophe).
Etymology - The word means "it lacks" in Latin.
Oxford English Dictionary - Its first citation is from 1710:
"That which is called Caret (that is to say in English, it is wanting) markt with a Latine Circumflex, thus (^) which is to shew where a Word forgotten … and placed above the Line, is to come in."
(W. Mather Young Man's Companion (1727) 38)