A more thorough explanation:

Reasonable grounds refer to a situation where there is a reasonable belief that a person has committed or is committing a crime or that a place contains specific items connected with a crime. This belief is based on facts and evidence that would convince a reasonable person.

For example, if a police officer sees someone breaking into a house, they have reasonable grounds to suspect that the person has committed a crime. Similarly, if a person is found with drugs in their possession, the police have reasonable grounds to suspect that the person is committing a crime.

Under the Fourth Amendment, probable cause is required before an arrest warrant or search warrant may be issued. Probable cause is more than a mere suspicion but less than evidence that would justify a conviction. It is an objective standard that requires the facts to be such as would warrant a belief by a reasonable person.

In tort law, probable cause refers to a reasonable belief in the existence of facts on which a claim is based and in the legal validity of the claim itself. For example, if a person files a lawsuit claiming that they were injured in a car accident, they must have reasonable grounds to believe that the accident occurred and that the other driver was at fault.