The definition of an orphan is:
An orphan (from the Greek: ορφανός orphanós) is a child whose parents are dead or have permanently abandoned the child
I've seen Islamic websites which say that an child is an orphan when their father dies. I can't remember which website so I found one which states:
Any child (male or female) whose has no father or whose father has died and the child has not reached the age of understanding or marriage (+/- 16 years) will be classified as a yateem or an orphan in Islamic Jurisprudence.
Question: Why are orphans considered orphans when their father dies and not when both of their parents die?
Is there any Islamic evidence from the Qu'ran and Ahadith that proves the claim to be true? (The claim is the Islamic claim that a child is an orphan when their father dies)