summum genus

Summum genus, in its strictest sense, is that all-extensive term under which every object of whatever kind may be classed, and of every one of which it may be affirmatively predicated: the word which is generally used to denote such genus is substance, or, as some call it, being. ... ; thus by ornithologist, bird would be regarded as the summum genus under which he would arrange the different subdivisions of birds ...