term:

Advocate

advocate n

[Latin advocatus adviser to a party in a lawsuit, counselor, from past participle of advocare to summon, employ as counsel, from ad to + vocare to call]
1 : a person (as a lawyer) who works and argues in support of another's cause esp. in court
2 : a person or group that defends or maintains a cause or proposal [a consumer ]
[ad-və-kāt] vb -cat·ed
-cat·ing
vt
: to argue in favor of
vi
: to act as an advocate [shall for minority business "V. M. Rivera"]

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