1. 难解：abstrusely 难解地 | abstruseness 难解 | abstrusity 难解
2. 奥妙：abstruselyimpalpablyobscurelyunintelligibly 难解地 | abstruseness 奥妙 | absurderroneous 谬
3. 难解, 深奥：abstrusely || 难解地, 深奥地 | abstruseness || 难解, 深奥 | abstrusity || 难解, 深奥
4. 深奥/奥妙：abstrusely /难解地/深奥地/ | abstruseness /深奥/奥妙/ | absurd /不合理的/悖理的/无稽的/荒唐的/可笑的/谬/妄/
noun
1. the quality of being unclear or abstruse and hard to understand
Synonym: obscurenessobscurityreconditeness
2. wisdom that is recondite and abstruse and profound
e.g. the anthropologist was impressed by the reconditeness of the native proverbs