Abstruse means Hidden or Secret. One which is difficult to conceive of or apprehend, recondite.
Abstruse is used to describe a personality which is a very concealed and does not let out his thoughts to anyone.
The words which describe the word Abstruse are obscure, deep, profound, complex, hidden, esoteric, mysterious, incomprehensible, unfathomable, inscrutable, enigmatic, perplexing, puzzling, recondite, arcane, nebulous.
1. The person is a very reconciled in nature, filled with Abstruseness.
2. Abstrusity is the character of some people.