English for Today by Ganiu Abisoye Bamgbose (Dr GAB)
STEP-SIBLING or HALF-SIBLING?
A step sibling (brother or sister) is a child of your stepfather or stepmother with another person who is not your biological (= related by birth) parent:
Demola is an amazing step brother.
You share one parent with you half-siblings:
They love one another so much that no one knew they were half-siblings.
Note too that while a blood brother or blood sister could mean a sister birth, it equally means a man or woman he or she has sworn to treat as a brother, often in a ceremony which involves mixing a small amount of their blood.
GAB
No comment