| Term | Definition |
| capillary | (n) Any of the tiny blood vessels that connect the smallest arteries to the smallest veins. (adj) Small and slender, with a very small internal diameter. |
| convalescence | (n) Gradual return to health and strength after an illness or other problem. |
| enervate | (v) To weaken; to destroy strength. |
| epidemiology | (n) The branch of medicine that deals with the causes, spread, and control of disease in populations. |
| epidermis | (n) The protective outer skin of vertebrates. |
| infirmity | (n) A physical disability or weakness. |
| malady | (n) A disease, ailment or disorder. |
| pallor | (n) Extreme or unnatural paleness. |
| susceptible | (adj) Likely to be infected or made ill. Easily influenced or affected; sensitive. |
| virulent | (adj) Capable of causing infection; very harmful or poisonous. Strongly and bitterly hateful. |