An action or situation that's detrimental does some kind of harm, like breaking a bone. It can also describe something that has negative effects over time.
Detrimental often shows up when we talk about things affecting people's health, relationships, or environment. For example, smoking is considered detrimental to your lungs and overall well-being. If someone says that social media use is detrimental to mental health, they mean it's bad for our minds. Even with objects, like a car seat that isn't installed correctly – being used in that way can be detrimental to the child's safety.
Causing damage or harm.
Example: Smoking tobacco can be detrimental to your health.
