Plat"i*tude (?), n. [F., from plat flat. See Plate.]
1.
The quality or state of being flat, thin, or insipid; flat commonness; triteness; staleness of ideas of language.
To hammer one golden grain of wit into a sheet of infinite platitude.
Motley.
2.
A thought or remark which is flat, dull, trite, or weak; a truism; a commonplace.
© Webster 1913.