(N.) ‘mum-bul-nim  Word you don’t know how to pronounce, usually because you’ve seen it written but never heard it spoken, like “misled” or “awry.” Usage: Marc cringed when Karen told their hosts  that the cabaret was “lowsh.”He realized that “louche” was a mumblenym for her—she’d only seen it in writing, so she didn’t know it was pronounced “loosh.”

—§ Note: MUMBLENYM is an old favorite, and appears in the Wordbirds book—§