Crabs: another name for pubic lice.

Dermatologist: doctor who specializes in skin diseases.

Host: plant, animal, or person that parasites live on.

Lice: plural for louse.

Louse: small crawling insect that infests host animals and humans and feeds on their blood.

Nit: louse egg.

Parasite: plant or insect that lives in or on other living things.

Pediculosis: being infested with lice.

Permethrin: man-made version of pyrethrum.

Pyrethrin: insecticide derived from pyrethrum.

Pyrethrum: natural insecticide that comes from the pyrethrum daisy, a kind of chrysanthemum. Used in over-the-counter lice treatments.