What's a mlem?
[I’m glad you asked, friend! Welcome to the First Temple of the Holy Mlem, I’ll be your guide.
“Mlem” is a onomatopoeia for the noise made by the sticking out of a tongue and immediately drawing it back into the mouth. (Urban Dictionary will back me up on this one.)
The mlem noise is not exclusive to any one particular type of animal, but is frequently ascribed on the internet to the tongue antics of cute cats and lizards. Within the FFXIV community, however, a “mlem” is usually an affectionate term for au ra characters. A mlem could be Raen or Xaela, it is not specific.
Alternative onomatopoetic terms for “that tongue thing” are “thip” or “blep”. However, mlem is the superior term, no matter what anyone else will tell you.]