From Gradus ad Parnassum (Latin, literally, a step to Parnassus), a 17th century prosody dictionary long used in British schools.
Gradus Sentence Examples
gradualis, of or belonging to steps or degrees; gradus, step), advancing or taking place by degrees or step by step; hence used of a slow progress or a gentle declivity or slope, opposed to steep or precipitous.
An account of them was published in 1755, entitled De Litteraria expeditione per pontificam ditionem ad dimetiendos duos meridiani gradus a PP. Maire et Boscovich.
The second part, Skaldskapar-mal, a gradus of synonyms and epithets, which contains over 240 quotations from 65 poets, and ro anonymous lays - a treasury of verse - was composed c. 1230.