Glossary
Retainer
A payment to a lawyer to secure their services for a case. Retainers can be one-time fees that cover defined work or refundable deposits that the lawyer bills against as work is done.
The word "retainer" gets used in different ways. A "true retainer" is a non-refundable fee paid to a lawyer just to keep them available: like a reservation. A "security retainer" is a deposit held in trust that the lawyer draws against as they bill for work, and any unused balance is refunded.
Most retainers in everyday legal work are security retainers. The fee agreement should spell out exactly which kind it is, the hourly rate, what gets billed, and what doesn't.