What is another word for knuckler?
Pronunciation: [nˈʌklə] (IPA) 
The word "knuckler" is often used to describe someone who is tough, unyielding or stubborn. There are many synonyms that can be used to describe someone or something with these attributes. Some synonyms for "knuckler" include stalwart, steadfast, resilient, tenacious, unyielding, inflexible, and immovable. Other synonyms may include headstrong, obstinate, dogged, determined, or hardheaded. All of these words describe someone who is unwilling to bend or compromise in their beliefs or actions. Whether you are describing a person or an object, it is important to choose the right synonym to convey the intended meaning.
