1.
user; one who uses something
A person who uses a product, tool, service, or substance. The everyday, general meaning.
この機械の使用者は注意してください。
Users of this machine, please be careful.
薬の使用者が増えている。
The number of users of the drug is increasing.
ソフトウェアの使用者は利用規約に同意する必要がある。
Users of the software must agree to the terms of use.
2.
employer (labor law)
In labor law and industrial relations, the party that employs workers—the counterpart of 労働者 (worker). Refers to the company or individual bearing an employer's legal duties.
使用者と労働者が話し合う。
The employer and the workers discuss the matter together.
使用者には安全配慮義務がある。
Employers have a duty to ensure safety.
労働条件をめぐって、使用者側と組合が対立した。
Over working conditions, the employer's side and the union came into conflict.
Composed of 使用 (use) + 者 (person). The everyday sense is "user"; the legal sense "employer" is standard in labor law, where it pairs with 労働者 (worker).
COMMON COLLOCATIONS:
- 使用者責任: employer's liability
- 使用者側: the employer's side
SIMILAR WORDS:
- 利用者: user — of a service or facility, more than a physical tool
- 雇用主: employer — plainer everyday word than the legal 使用者