Soft-pedal

verb (used without object), soft-pedaled, soft-pedaling or (especially British) soft-pedalled, soft-pedalling.
1.
to use the soft pedal.
verb (used with object), soft-pedaled, soft-pedaling or (especially British) soft-pedalled, soft-pedalling.
2.
to soften the sound of by using the soft pedal.
3.
Informal. to tone or play down; make less strong, as an idea or fact:
The dean soft-pedaled the reports of cheating.
noun
1.
Also called una corda pedal. a pedal, as on a piano, for reducing tonal volume.
2.
Informal. something that restrains or dampens:
to put a soft pedal on one’s enthusiasm.
verb (transitive) -als, -alling, -alled (US) -als, -aling, -aled
1.
to mute the tone of (a piano) by depressing the soft pedal
2.
(informal) to make (something, esp something unpleasant) less obvious by deliberately failing to emphasize or allude to it
noun
3.
a foot-operated lever on a piano, the left one of two, that either moves the whole action closer to the strings so that the hammers strike with less force or causes fewer of the strings to sound Compare sustaining pedal, piano1
noun

See damper pedal
soft money
Something that de-emphasizes, restrains, or plays down, as in The mayor put a soft pedal on this potentially explosive situation. This expression alludes to the una corda or soft pedal of the piano, which reduces the volume of the sound. It gave rise to the verb soft-pedal, meaning both “reduce the volume of” or “make less emphatic, downplay.” [ Early 1900s ]