pilo-, pil-, pili- +

(Latin: hair)

Don't confuse the words in this pilo-, pil- group with the pil- or "plunder, heap up" unit.

pilation, pilatio
A hairline fracture that may be found in skull bones.
pileous
Covered with hair.
pileum (s), pilea (pl) (nouns)
The top of a bird's head, from the nape (back part of the neck) to the bill (bird's beak or mouth part).
piliation
The formation and growth of hair.
piliferous, piligerous
1. Used to describe plant parts that are covered in fine hairs or have hairs growing at the tip.
2. Bearing or producing hair; the outermost layer of root or epiblema that gives rise to root-hairs.
piliform
A reference to a plant part that takes the form of a hair; resembling hair; trichoid.
pilimiction, pilimictio
The passage in the urine of hairs or hairlike structures, such as threads of mucus.
piline: hair
Of the nature of hair, hairy.
pilo hair
Various words about "hair" as seen in this pilo unit.
pilocystic
Hollow, or cystlike, and containing hairs; said of certain dermoid tumors.
pilocytic
Composed of fiber-shaped cells.
piloerection
1. A skin reaction caused by erection of the hair follicles, as from cold or shock due to contraction of the arrector pili muscles. This causes transient roughness of the skin.
2. An involuntary erection or bristling of hairs due to a sympathetic reflex usually triggered by cold, shock, or fright, or due to a sympathomimetic agent.

"Goose bumps" (American English), also called "goose pimples", "goose flesh" (British English), "chicken skin" (Hawaiian Pidgin), or cutis anserina, are the bumps on a person's skin at the base of body hairs which involuntarily develop when a person is cold or experiences strong emotions; such as, fear. The reflex of producing goose bumps is known as horripilation or pilomotor reflex. It occurs in humans and in other mammals.

Piloerection starts when a stimulus such as cold or fright causes a discharge from the (involuntary) nervous system that triggers a contraction of the little arrectores pilorum muscles. Contraction of these muscles elevates the hair follicles above the rest of the skin so the hair seems to "stand on end".

piloid
Resembling hair.
pilojection
The introduction of hair into an aneurysm to promote obliteration by producing thrombosis in the aneurysm.
pilology
The study of hair; also trichology.