名词

1. 定金;预付金
A retainer is a fee that you pay to someone in order to make sure that they will be available to do work for you if you need them to.

2. （服务多年的）仆人，家仆
A servant who has been with one family for a long time can be referred to as a retainer .

1. a dental appliance that holds teeth (or a prosthesis) in position after orthodontic treatment

2. a person working in the service of another (especially in the household)

Synonym: servant

3. a fee charged in advance to retain the services of someone

Synonym: consideration