| Term | Definition | Pronunciation |
| K | potassium | |
| kal/i | potassium | |
| kary/o | nucleus | |
| kel/o | tumor, fibrous growth | |
| keloid | An overgrowth of scar tissue that develops around a wound | ke´loid |
| kelp | A type of seaweed. | |
| ken/o | empty | |
| kerat/o | cornea, horny, hard | |
| keratin | A family of fibrous proteins that are principle constituents of epidermis; hair; nails; horny tissues, and tooth enamel. | |
| keratitis | Inflammation of the cornea | ker″ah-ti´tis |
| keratoconjunctivitis | Inflammation of the cornea and conjunctiva. | |
| keratoconus | A conical protrusion of the central part of the cornea. | |
| keratosis | Any horny growth of the skin such as a wart or callus. | |
| ketonuria | Presence of ketone bodies in urine. | |
| ketosis | Abnormally high concentration of ketone bodies, as in diabetes mellitus. | |
| kg | kilogram | |
| kidney | One of a pair of organs that filter blood for the secretion of urine and that regulates ion concentrations. | |
| kilo- | one thousand | |
| kilogram | Unit of mass equal to one thousand grams. | |
| kinesi/o | movement | |
| kinesics | The study of body position motion in communication. | |
| kinesis | Movement of an organism in response to a stimulus | |
| kinetics | The study of the interrelationships that exist between body parts and how those connections influence movement. | |
| klept/o | to steal | |
| kleptomania | An abnormal, strong impulse to steal. | |
| km | kilometer | |
| knee | The joint between inferior femur and superior | |
| koil/o | hollow, concave | |
| koilonychia | A disease of the fingernails, where they become thin and concave. | koi″lo-nik´e-ah |
| kraur/o | dry | |
| KS | Kaposi sarcoma | |
| KUB | kidney, ureter, and bladder | |
| kv | kilovolt | |
| KVO | keep vein open | |
| kym/o | waves | |
| kyph/o | bent, hump | |
| kyphosis | Deformities of the spine characterized by an exaggerated convexity of the vertebral column. Sometimes called round back or hunchback. | ki-fo´sis |