esoteric
adjective \ess-uh-TAIR-ik\
1 : designed for or understood by those with specific knowledge or training : difficult to understand
2 a : limited to a small circle
b : private, confidential
3 : of special, rare, or unusual interest
Did You Know?
The opposite of esoteric is exoteric, which means “suitable to be imparted to the public.” According to one account, those who were deemed worthy to attend the Greek philosopher Aristotle’s learned discussions were known as his “esoterics,” his confidants, while those who merely attended his popular evening lectures were called his “exoterics.” Since material that is geared toward a target audience is often not as easily comprehensible to outside observers, esoteric acquired an extended meaning of “difficult to understand.” Both esoteric and exoteric started appearing in English in the 17th century; esoteric traces back to ancient Greek by way of the Late Latin esotericus. The Greek esōterikos is based on the comparative form of esō, which means “within.” – from www.merriam-webster.com
