Final answer:
Failure to attain or maintain an adequate erection during sexual activity is characteristic of Erectile Dysfunction.
Step-by-step explanation:
Erectile Dysfunction (ED) refers to the inability to achieve or maintain an erection that is sufficient for satisfactory sexual performance. It's a common condition that can be caused by various factors, including physical issues, psychological factors, or a combination of both. ED can significantly impact sexual relationships and overall quality of life for affected individuals.