The oil can, used in the 1939 classic, is thought to be the last original item left from the Tin Man's iconic costume A piece of cinematic history from the classic film The Wizard of Oz will soon be ...
Merriam-Webster has an entry for half-orphan, meaning someone with only one living parent. They say specifically a child, which would match the usual usage of "orphan" (as mentioned in the question), but it might be used of an adult sometimes, either jocularly or by extension. This doesn't distinguish which parent is dead, but could be combined with a further explanation if it matters.
16 The word adult appear to have derived from the Latin term adultus, meaning grown up, mature, adult, ripe. Adulterate (and its cognate adultery) is reported to derive from the Latin adulterare - to falsify, corrupt. Are the meanings and derivation of adult and adulterate, directly related, or is this just a coincidence of spelling?
People: 'Wizard of Oz' 's Tin Man Oil Can Up for Auction for the First Time, Bidding Starts at $50,000
'Wizard of Oz' 's Tin Man Oil Can Up for Auction for the First Time, Bidding Starts at $50,000