Stiff-necked is an adjective that describes someone who is stubbornly resistant or inflexible in their opinions. Here are some synonyms for the word stiff-necked: obstinate, unyielding, rigid, dogmatic, adamant, bullheaded, intransigent, inflexible, stubborn, and resolute. Many of these words convey a negative connotation and suggest that a person is unwilling to change their beliefs or behavior, even when presented with evidence to the contrary. However, some of these words also imply a certain level of determination or conviction, which can be a positive trait in certain situations. Ultimately, the choice of synonym depends on the context in which the word is being used.