Image via Wikipedia
Labial: adjective - of or pertaining to the lips; designating sounds that need complete or partial closure of the lips for formation, like the consonants /p/, /b/, /m/, /f/, /v/, /w/, and vowels for which the lips are rounded; associated with, of the nature of, or located on a lip or labium.
'The speech therapist insisted on the proper pronunciation of those labial consonants, emphasising the sound as she spoke each word in turn; "potty, bottom, moron, fatty, vulgar and walrus", though she insisted her chosen words were not related to her portly student.'
'Tenderly toying with her hair and moving in closer, he noted that some strands, close to the opening, were labial.'
By the way, reminder to my UK readers. Today is census day; don't forget to fill in your forms and keep those statisticians out of mischief.