"Dyed in the wool" is a unique phrase used to describe someone or something that is completely fixed in a particular pattern or way of thinking. Some possible synonyms for this phrase include "firmly entrenched," "entrenched," "ingrained," "deeply rooted," "devoted," "steadfast," "committed," "unwavering," "uncompromising" and "hardcore." All of these adjectives convey a sense of stubbornness and determination that is central to the meaning of "dyed in the wool." Whether talking about a person's beliefs, a political ideology or a particular way of doing things, these synonyms highlight the unyielding nature of the subject at hand.