Which combining form means having four or consisting of four?

• A. Myc/o
• B. Quadr/i
• C. Chol/e
• D. Aden/o

Answer: (B)

Four is signaled by the combining form quadr/i-. It literally means four or fourfold and is used to form terms describing four of something, such as quadrilateral, quadriplegia, or quadruplet. The other forms refer to fungus (myc/o), bile (chol/e), and gland (aden/o); none convey the sense of “four.”