Final answer:
Bartholin's glands provide lubrication for the vagina.
Step-by-step explanation:
The primary function of Bartholin's glands is to provide lubrication for the vagina. These glands produce a thick mucus that maintains moisture in the vulva area. Secretions from Bartholin's glands near the vaginal opening lubricate the vulva, facilitating sexual intercourse and reducing discomfort or friction.