The word "labial" refers to something related to the lips. It can describe sounds or actions involving the lips, such as when speaking certain letters like 'p' or 'b' that require lip movement. Full definition
Lip ties are unusually short or tight labial frenulums and are discussed with increasing frequency. (doulasofcincinnati.com)
Dotson allows us a glimpse at The Beast's rapacious grimace, cast in the shadow from the glow of the lush labial folds of the rose as it hovers just beyond the fragile glass he clutches, it's juicy segments begging to be touched. (arthaps.com)
Labial frenums can also have a negative impact of breastfeeding because they may not allow for the flaring of the upper lip that is needed to create a good seal around the breast. (brianpalmerdds.com)