From Wikipedia, the free encyclopedia. Acetic anhydride, or ethanoic anhydride, is the chemical compound with the formula (CH 3 CO) 2 O. Commonly abbreviated Ac 2 O, it is the simplest isolable anhydride of a carboxylic acid and is widely used as a reagent in organic synthesis.o a decreasing extent, acetic anhydride is also prepared by the reaction of ketene (ethenone) with acetic acid at 45â55 Â°C and low pressure (0.05â0.2 bar).
Definition: The prefix (eu-) means good, well, pleasant or true. It is derived from the Greek eu meaning well and eus meaning good. Eubacteria (eu-bacteria) - kingdom in the bacteria domain. Bacteria are considered to be true bacteria, distinguishing them from archaebacteria.
Euphemism Definition. The term euphemism refers to polite, indirect expressions that replace words and phrases considered harsh and impolite, or which suggest something unpleasant. Euphemism is an idiomatic expression, which loses its literal meanings and refers to something else, in order to hide its unpleasantness. For example, âkick the bucketâ is a euphemism that describes the death of a person.