Don't like those synonyms

Question

Stand alone

I am someone with authority

Add a "B" or an "H" or an "L"

All three are synonyms of each other

Who am I?

Answer 1

I think the answer is

Ump

Stand alone
I am someone with authority

Ump is short for "umpire" - an official who watches a game or match closely to enforce the rules

Add a "B" or an "H" or an "L"
All three are synonyms of each other

Bump, Hump and Lump are all, essentially, synonyms of each other (a protuberance).

Explanation of the Title (from OP in the comments)

Bumps, humps and lumps are often disliked (especially on one's body).