What is ‘Rime Icing?’

Around eastern Iowa, the trees have resembled something you'd see on a frozen planet or perhaps on a Bob Ross painting, the last few foggy mornings. It's called 'Rime Icing." What is it?

Dictionary.com defines it as:

an opaque coating of tiny, white, granular ice particles, caused by the rapid freezing of supercooled water droplets on impact with an object.

However you want to describe it or whatever you call it --- it's been beautiful to see hanging from the tree the past few days.