noun
person willing to take on a role; willing candidate
Refers to someone who is willing to assume a position, role, or responsibility, often in contexts where finding such a person is difficult.
会長のなり手が見つからない。
We can't find anyone willing to become the chairperson.
この仕事はきついので、なり手が少ない。
This job is tough, so there are few willing candidates.
候補者 is a general 'candidate' for a position, while なり手 specifically emphasizes willingness to take on a role, often used when such people are scarce.
Compound of the continuative form of なる (to become) and 手 (person). The exact historical derivation is uncertain, but the word has been used since at least the Edo period.