That means to play something down, to make it harmless.

You know, like the ideology pursued by the murdered “revolutionary socialists” (communists) Rosa Luxemburg and Karl Liebknecht that gets played down, made harmless? They are worshiped as cult figures by the German left. They might even beat Che Guevara in the pantheon of mythical, romantic demigods of the revolutionary left. They may not have been the monster that guy was but that’s only because they didn’t have the time to get there.
On Sunday morning, some 10,000 people braved the rain and cold to march through eastern Berlin and place red carnations at the graves of Rosa Luxemburg and her comrade, Karl Liebknecht.
The march was commemorating 100 years since the brutal execution of the two revolutionary socialists on January 15, 1919…
In November 1918, a revolt by sailors and soldiers led to the overthrow of the Hohenzollern monarchy and the end of the war. In December, the Spartacist League renamed itself the German Communist Party (KPD) and Luxemburg asserted that they would not try to seize power without the support of the majority of Germans. Yet when a second revolt broke out on January 5, 1919, she and Liebknecht gave the movement their full support. The uprising quickly faltered and the SPD leadership ordered the army and right-wing paramilitaries, the Freikorps, to crush it.
On the night of January 15, Luxemburg and Liebknecht were abducted, tortured in the luxury Hotel Eden, and then driven separately to the nearby Tiergarten Park and murdered. Liebknecht was delivered to the city morgue while Luxemburg was dumped into a canal.
“Those who do not move, do not notice their chains.”