Final answer:
The medical word formed by peri- (around), cardi/o- (heart), and -al (pertaining to) is pericardial, and it refers to something that pertains to the pericardium, meaning 'Around the heart'.
Step-by-step explanation:
The medical word formed by the word parts peri- (around), cardi/o- (heart), and -al (pertaining to) is pericardial. This term refers to something that pertains to the pericardium, which is the membrane that directly surrounds the heart, providing protection and maintaining the heart's position in the thorax. Therefore, the correct definition for this term would be 'Around the heart'.