Labialization
Under Labialization (also: rounding ) is called both the process of secondary articulation and the going back to lip rounding sound change (see: diachrony ) in phonetics. So the rounded front vowels of the New High German language caused by Labialization. From the Middle High German word leffel was spoon.
In the languages of the Caucasus, the Labialization of consonants has a distinctive function.
Other types of secondary articulation are: palatalization velarization, laryngealization, Glottalisierung and pharyngealization.