1) Tenacious: This means persistent and does not necessarily mean bossy. It describes a good/positive mentality or behavior but not in relation to another individual or group. The other words could easily be synonyms for 'bossy' because they are related to one person's attitude or behavior towards another person in a very negative context.

Which word can't be a synonym for the word 'bossy?' You mean ' can be ' ? Bossy > domineering is the closest to bossy . Boss dominates all in office . tenacious > having a quality of never giving up on something while you are determined to do it . Their tenacious attacks on the enemies.../He is a tenacious boss : he will try all he can to keep profits up, even though its a challenge this year dictatorial and authoritarian are similar in meaning : you cant say no to them coz they have absolute power So, the best word are domineering , then dictatorial or authoritarian , depending on the extend of his bossy behavior . Opposite > submissive boss