This is the 16815th most frequent Russian word.
смягчающее
Softening.
The word 'смягчающее' acts as an adjective describing 'средство', referring to a product that has a soothing or softening effect.
Смягчающее средство помогает при сухости кожи.
A softening agent helps with dry skin.
Here, 'смягчающее' describes 'влияние', indicating an effect that alleviates tension or makes situations more pleasant.
У него есть смягчающее влияние на окружающих.
He has a soothing influence on those around him.
In this instance, 'смягчающее' modifies 'вещество', which implies an ingredient that alters the properties of the solution to become more pliable or less harsh.