Mawson, C.O.S., ed. (1870–1938). Roget’s International Thesaurus. 1922.
Class III. Words Relating to MatterSection I. Matter in General
4. Motion with Reference to Direction
320. Levity.
[COMPARISONS] feather, dust, mote, down, thistledown, flue, fluff, cobweb, gossamer, straw, cork, bubble; float, buoy; ether, air.
FERMENT, leaven, barm, yeast, zyme, enzyme, pepsin, diastase.
RENDER LIGHT &c. adj.; lighten.
FERMENT, work, raise, leaven.
light as -a feather, – thistledown, – air.
FERMENTING, fermentative, zymogenic, zymologic or zymological, diastatic, yeasty.