The term 'unwilling to budge' can be described by a variety of words, all of which have similar meanings. These words include OBSTINATE (9 letters), OBDURATE (8 letters), PIGHEADED (9 letters), ADAMANT (7 letters), FIRM (4 letters), STUBBORN (8 letters), and STUCK (5 letters). All of these words refer to someone who is unwilling to change their opinion or position on something, even when faced with strong opposition. This type of behavior is often seen as unyielding and inflexible.