unrelated
adj. B2 Upper Intermediate US //ˌənɹiˈɫeɪtɪd// UK //ˌʌnɹɪlˈeɪtɪd// un·re·lat·ed
adj. not connected to something else in any way. You use this when two things happen at the same time but have no common cause or link.
adj. having no connection or association; lacking a logical or causal link to something else. Often used to clarify that a coincidence is not a result of a specific relationship.
The two problems are completely unrelated.
The doctor explained that my headache was unrelated to the medicine I started taking last week.
Although the two events occurred on the same afternoon, police believe they are entirely unrelated and were carried out by different groups.
From un- + related.
Usage
Typically used as a predicative adjective following a linking verb or as an attributive adjective before a noun.