to be willing: to consent and go along with what someone else asks or wants
This verb is about giving in to another person's wish. It is not the inner spark of wanting something for yourself; it is the moment you bend your own will to fit what someone is asking of you, the yes that lets their request happen. Because of that, it usually appears where one party is pressing and the other decides whether to comply.
The most striking thing about the word is how rarely anyone in the Hebrew Bible actually does it. Out of roughly fifty uses, the overwhelming majority are negative: someone was not willing, would not, refused. Pharaoh would not let Israel go, kings would not make peace, Israel would not listen to God. The word becomes a near-synonym for stubborn refusal simply because that is the situation it keeps naming. The few positive uses stand out by contrast, most famously the offer in Isaiah, "If you are willing and obey, you will eat the good of the land."
When it does appear without a flat denial, it is often a question or a condition probing whether someone will agree, as when Abraham's servant worries the woman may not be willing to follow him, or when Job is asked whether a wild ox would ever consent to serve. In every case the focus is the same: not desire, but assent, the choice to yield to another.