term:

Retainer

retainer n

[Anglo-French retener act of engaging or employing, from retener retenir to engage, retain]
1 : the act of a client by which the services of a lawyer are engaged
2 : a fee paid to a lawyer for advice or services or for a claim on services when needed

Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.