ab-

from the GNU version of the Collaborative International Dictionary of English.

• A prefix in many words of Latin origin. It signifies from, away , separating, or departure, as in abduct, abstract, abscond. See a-(6).

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• prefix physics an electromagnetic unit in the centimeter-gram-second system: abcoulomb.
• prefix non-productive From
• prefix non-productive Away from; outside of.