How do you spell Abbreviating

Available Definitions:
1)  v. t. - To make briefer; to shorten; to abridge; to reduce by contraction or omission, especially of words written or spoken.
2)  v. t. - To reduce to lower terms, as a fraction.
3)  a. - Abbreviated; abridged; shortened.
4)  a. - Having one part relatively shorter than another or than the ordinary type.
5)  n. - An abridgment.