What is the contraction of a word by the omission of a letter or letters, which omission is marked by the character ['] placed where the letter or letters would have been; as, call'd for called called?

apostrophe — (Gram.) The contraction of a word by the omission of a letter or letters, which omission is marked by the character ['] placed where the letter or letters would have been; as, call'd for called. (Webster's 1913.)