Abbreviations Frequently Encountered
(shortened forms of spoken words or written symbols, or phrases, used chiefly in writing to represent the complete forms)
1. Being in physical motion; such as, active fish in the aquarium.
2. Functioning or capable of functioning.
3. In grammar, idicating that the subject of the sentence is performing or causing the action expressed by the verb.
Referring to a verb form or voice; used with verbs; such as, run, speak, and move: "I run, You run, He, She, It runs."
Literally meaning is "at pleasure". This expression is popularly used as a noun phrase or modifier in English in the form "ad lib" to express absence of planning; for example, "His worst jokes were carefully planned ad libs."