noun. A bulb: used chiefly in anatomy in such phrases as bulbus oculi, the eyeball; bulbus aortæ, the aortic bulb.

"It is a result of the swelling of the bulbus glandis or “knot” swelling at the time of ejaculation."

bulbus arteriosus  bulbus glandulosus  bulbus venæ jugularis  

orbicularis  praesentis  sicuti  vident