Flat"ten (?), v. t. [imp. & p. p. Flattened (?); p. pr. & vb. n. Flattening.] [From Flat, a.]
1.
To reduce to an even surface or one approaching evenness; to make flat; to level; to make plane.
2.
To throw down; to bring to the ground; to prostrate; hence, to depress; to deject; to dispirit.
3.
To make vapid or insipid; to render stale.
4. Mus.
To lower the pitch of; to cause to sound less sharp; to let fall from the pitch.
To flatten a sail Naut., to set it more nearly fore-and-aft of the vessel. -- Flattening oven, in glass making, a heated chamber in which split glass cylinders are flattened for window glass.
© Webster 1913.
Flat"ten, v. i.
To become or grow flat, even, depressed dull, vapid, spiritless, or depressed below pitch.
© Webster 1913.