Mawson, C.O.S., ed. (1870–1938). Roget’s International Thesaurus. 1922.
Class II. Words Relating to SpaceSection III. Form
3. Superficial Form
251. Flatness.
NOUN:FLATNESS &c. adj.; smoothness [See Smoothness].PLANE; level [See Horizontality]; plate, platter, table, tablet, slab.
VERB:FLATTEN; render flat; squelch [colloq.], squash [colloq.], fell; level [See Horizontality].
ADJECTIVE:FLAT, plane, even, flush, scutiform, discoid; complanate, flattish, homaloid; level (horizontal) [See Horizontality]; flat as – a pancake, – a fluke, – a flounder, – a board, – my hand; smooth.
ADVERB:FLAT, flatly [rare], flatways, flatwise, lengthwise, horizontally.