rarer
adj.adj. not happening or found very often. It is the comparative form of 'rare', used to compare two things that are both hard to find.
adj. the comparative form of 'rare'; occurring or found less frequently than another thing. Typically describes objects, events, or conditions that are uncommon or unusual.
This blue diamond is even rarer than the white one.
While seeing a fox in the garden is unusual, seeing a badger is much rarer in this part of the country.
The collector explained that while the first edition is difficult to source, the signed version is significantly rarer and commands a much higher price at auction.
Comparative adjective — typically followed by 'than' when comparing two specific items.
more rarerrarerRarer is already a comparative form; adding 'more' creates a double comparative error.