My parents Bianca and Ivan are currently married and have always been since before I was born. Both of my parents have had previous relationships in the past. Bianca had a previous relationship with Henry and have a son named John, making John my half brother. Ivan had a previous relationship with Alicia, and have two sons named Frank and Ernest, making Frank and Ernst my half brothers. After that, Ivan met Katy and have a daughter named Pamela, making Pamela my half sister. So basically, I have one brother from my mom’s side and two brothers and one sister from my dad’s side. John knows who my other half siblings are but he doesn’t know them at all and he barely sees them. Is he related to them?Is there a term for this relationship? I suspect he really isn’t but I’m just curious.
According to today's standards, they're not truly related.
However, they are members of the same clan.
Also, less than 500 years ago, if John and Pamela had a relationship, it would have been considered incestuous: a sibling was a true sibling once he or she had been recognized as such. This had to do with the Christian view of the family as a concept, I think (which is why, for instance, Shakespeare's Hamlet views his mother's marriage to his uncle as incestuous).
The answer to your question depends on your understanding of the word related.
Oxford defintes related as:
related - adjective - Belonging to the same family, group, or type; connected.
In that sense you are absolutely related, but in another sense you might not be. Some people use the term related to refer to primary familial connections (father, mother, sister, brother, cousin.) In the eyes of such a person, you wouldn't be related unless you shared familial DNA.
In my opinion that definition is too narrow. Ultimately, all humans are related, and we are genetically related to other mammals. The important thing is, are you family?