The expression "hath relation" is an archaic form of "has a relation." The pronunciation of "hath" is /hæθ/, with the "th" sound being a voiceless dental fricative produced by sticking the tip of the tongue between the upper and lower teeth and blowing out air. It was commonly used in Early Modern English, but its use has declined over time. Nowadays, the more common usage would be 'has', which is much easier to spell and pronounce.
The phrase "hath relation" is not a standalone word; it is a combination of two words: "hath" and "relation".
1. "Hath": This is an archaic form of the verb "have" in third-person singular present tense. It was commonly used in Early Modern English (16th-17th centuries) and can still be found in old texts, plays, and religious literature. For example, "hath" is used in the famous Shakespearean phrase "to be, or not to be, that is the question".
2. "Relation": This word comes from the Latin word "relatio" meaning "a bringing back" or "a report". It evolved in Middle English around the 14th century and has remained relatively unchanged since.