Final answer:
The word part -osis refers to an abnormal condition, and cyanosis is a bluish discoloration of the skin due to lack of oxygen in individuals with certain heart defects.
Step-by-step explanation:
The given word part -osis refers to an abnormal condition. When a person is bluish or purplish in color due to insufficient oxygen supply, it is called cyanosis. This condition can occur in individuals with severe heart defects such as tetralogy of Fallot or patent foramen ovale. Regardless of their skin pigmentation, the lack of oxygenated blood leads to the bluish discoloration of the skin, especially during physical activity.