What is the term for weakness and/or paralysis of an extremity?

The term that describes weakness and/or paralysis of an extremity is "paresis." Paresis refers to a condition characterized by partial loss of motor function, resulting in weakness in the affected limb. This can manifest as difficulty in movement or reduced strength, impacting an individual's ability to perform daily activities.

In contrast, paraplegia refers specifically to paralysis that affects the lower limbs and usually results from spinal cord injuries or certain neurological conditions. While this condition does involve paralysis, it is more specific than paresis, which encompasses a broader range of weakness.

Pathology denotes the study of disease, and does not directly refer to any specific condition or symptom like weakness in an extremity. Lastly, a parasite refers to an organism that lives on or in a host and derives nutrients at the host's expense, which is unrelated to the paralysis or weakness of limbs.