Bonus, n.; pl. Bonuses (.
Etymology: [L. bonus good. Cf. Bonny.]
1. (Law)
A premium given for a loan, or for a charter or other privilege granted to a company; as the bank paid a bonus for its charter. Bouvier.
2. An extra dividend to the shareholders of a joint stock company, out of accumulated profits.
3. Money paid in addition to a stated compensation.
Shades of meaning
Fernald has no entry of its own for bonus; he lists it under subsidy.
He lists it without comment; the entries above explain its neighbors.