lactiferous: adjective, Latin lac = milk, and ferre = to carry.
lacuna: Latin lacus = lake, hence, a small pond or gap, adjective, lacunar.
lambda: Greek letter representing a capital 'L' and written as an inverted V.
lambdoid: adjective, Greek lambda, representing a capital 'L' and written as an inverted V; hence, like that letter.
lamella: diminutive of Latin lamina = plate; hence, a small plate.
lamina: Latin = plate, either a layer of nervous tissue, like the laminae of the lateral geniculate body, or a connective tissue membrane, like lamina cribrosa sclerae, or of bone, as in vertebral laminae; hence, laminectomy = lamina + Greek ektome = excision - excision of the vertebral laminae to give access to the spinal cord; adjective - laminar.
lanugo: Latin lana = wool, hence, the fine downy hair on the skin of the foetus, or cheeks.
ligament: Latin ligamentum = bandage, usually tying parts to each other, adjective - ligamentous.
limbic: adjective, Latin limbus = a margin, usually curved.
limbus: Latin = a margin, usually curved, hence, limbus of cornea, its circular junction with the sclera, adjective - limbic; limbic lobe of the brain comprises structures which encircle the junction of the diencephalon and telencephalon.
limen: Latin = a threshold, hence, subliminal - below threshold.