Which combining form means pertaining to the fingernails?

• A. Onych/o
• B. Physic/o
• C. Proxim/o
• D. Neur/o

Answer: (A)

Onych/o designates the nail, covering fingernails and toenails. In medical terms, this root is used when describing anything related to nails, so it’s the best fit for something pertaining to the fingernails. For example, words built with this root include onychomycosis (fungal infection of the nail) and onychoplasty (surgical repair of a nail). The other roots describe unrelated concepts—physic/o refers to nature or physical aspects, proxim/o means near or proximal, and neur/o relates to nerves—so they don’t convey nail-related meaning.