flatten-v; 4 Senses

Sense Number 1: make or become thinner and/or more level

Examples:
During cooking the dough flattens somewhat to resemble a cookie.
The neck loses its roundness and shows the sinews, the chest flattens.

Mappings:
VerbNet: carve-21.2-1,other_cos-45.4
FrameNet: Reshaping
PropBank: flatten.01,flatten.02
WordNet 3.0 Sense Numbers: 1, 2
WordNet Verb Particle Constructions, Multiword Expressions:
flatten_out 1

Sense Number 2: to make dull, insipid, lusterless

Examples:
Although the combination is an interesting one, the flavors flattened out with no clear sense of dimension.
Halfway through my Coke flattened out the flavor, and basically ruined the cigar.
The interesting thing was, the wine flattened the stew.
The wine flattened out and seemed to have little of distinction about it.
At first they looked like kitchen matches, but the paint flattened out when it dried.

Mappings:
VerbNet: NM
FrameNet: NM
PropBank: NM

Sense Number 3: become uniform or stabilized, usually at a lower level

Examples:
Russo-Vietnamese relations flattened out after their decline as both sides understood there were advantages in maintaining them.
The hidden social dynamics were flattened out by the Berlin topography.
She stated that Bell South advised that the cost has flattened out already.
U.S. stock futures flattened out Tuesday after early losses.

Mappings:
VerbNet: NM
FrameNet: NM
PropBank: flatten.01,flatten.02

Sense Number 4: lower in pitch

Examples:
Over a count of 4, slacken your jaw so that the note flattens by approximately half a semitone.
Move the hole down the whistle, so that the note flattens by downward movement.

Mappings:
VerbNet: NM
FrameNet: NM
PropBank: NM
WordNet 3.0 Sense Numbers: 3