Oleomargarine is what margarine was originally called, sometimes shortened to 'oleo'. This makes it one of a select few: words which can be broken into two words, so that each of the two and the original word are synonymous. That is:
oleomargarine = oleo = margarine.
Can you find another two English words that share this property?
(In reply to
re(2): Huh?? (re: Two more) by TomM)
The original posting had more than those you mentioned, and was associated with other postings as well.... And while each particular pairing has varying degrees of success, the original criticism applied to the whole group of them.
You, also didn't mention man=servent or over=done, which are more reasonable. The others are still worthy of note, and with such a problem, your notion of "obviously right" is hard to swallow.
If one wants an "obviously right" answer, one should TD those problems that allow for multiple answers and/or "degrees of correctness".