We are asked for the one-word substitute for "an unconventional style of living." Let’s analyze the options:
Option (1): Misanthrope
A misanthrope is a person who dislikes or avoids human society, not related to lifestyle. This term does not fit the description of an unconventional style of living.
Option (2): Autonomy
Autonomy refers to the state of being self-governing or independent. While it may relate to certain aspects of unconventional living, it does not describe the lifestyle itself.
Option (3): Bohemian
A "Bohemian" refers to a person who leads an unconventional lifestyle, typically one that is artistic and free-spirited. This is a perfect fit for the description given in the question.
Option (4): Monarchy
Monarchy refers to a form of government where a monarch rules, which is unrelated to a lifestyle or living style.
Thus, Option (3) "Bohemian" is the correct one-word substitute.