of astrology
secret, concealed
of the brain
using one's brain
with a hidden meaning or a meaning not easily understood
secret; obscure in meaning
understood by, intended for, only a small number of people
mysterious, obscure
of hide
unseen, secret
using the latest technology
difficult, complex
based on thought and reasoning; (of poetry) intellectual and psychological, usually about themes such as love, religion and death
not physical; without physical presence
full of, suggesting, mystery
secret, concealed
hidden; not clearly seen; not easily understood; not well known
not easily understood
deep (the usual word); showing, having great knowledge
intellectual, thoughtful
(that is to be) kept from the knowledge or view of others; of which others have no knowledge
hidden, unrevealed
not well known; not knowing (about) something
different, strange