abevacuationMed.|ˌæbɪˌvækjuːˈeɪʃən| [f. L. ab off, from + evacuation; cf.ab-articulation.] ‘A partial or incomplete evacuation, whether naturally or artificially produced.’ Mayne 1851. Also ‘Evacuation which is effected by the passage of matter from one organ into another.’ Syd. Soc.Lex. 1879.