Moreso
The two-word form is still safer.
Minima vs. minimums
minima in science and mathematics; minimums in general usage.
Maddening vs. madding
The traditional form of the idiom is madding crowd.
Make hay
1. short for make hay while the sun shines, referring to the wisdom of taking advantage of opportunities before they go away; 2. to turn (something) to one’s advantage.
Macaron vs. macaroon
A macaron is a sandwichlike French confection. A macaroon is a light cookie often containing almonds or coconut.
