Here are some synonyms for pugnacious:
* Belligerent
* Combative
* Contentious
* Feisty
* Quarrelsome
* Argumentative
* Aggressive
* Antagonistic
Here are some examples of how to use the word "pugnacious" in a sentence:
* The pugnacious dog barked at every passerby.
* The politician was known for his pugnacious style of debate.
* Despite her small size, she had a pugnacious spirit.
Note: While "pugnacious" is often used to describe a person, it can also be used to describe animals or even things, such as a "pugnacious argument".