From WordNet (r) 3.0 (2006) [wn]:
lobby
n 1: a large entrance or reception room or area [syn:
anteroom, antechamber, entrance hall, hall,
foyer, lobby, vestibule]
2: the people who support some common cause or business or
principle or sectional interest
3: a group of people who try actively to influence legislation
[syn: lobby, pressure group, third house]
v 1: detain in conversation by or as if by holding on to the
outer garments of; as for political or economic favors
[syn: lobby, buttonhole]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Lobby \Lob"by\, n.; pl. Lobbies. [LL. lobium, lobia, laubia, a
covered portico fit for walking, fr. OHG. louba, G. laube,
arbor. See Lodge.]
1. (Arch.) A passage or hall of communication, especially
when large enough to serve also as a waiting room. It
differs from an antechamber in that a lobby communicates
between several rooms, an antechamber to one only; but
this distinction is not carefully preserved.
[1913 Webster]
2. That part of a hall of legislation not appropriated to the
official use of the assembly; hence, the persons,
collectively, who frequent such a place to transact
business with the legislators; hence: any persons, not
members of a legislative body, who strive to influence its
proceedings by personal agency; a group of lobbyists for a
particular cause; as, the drug industry lobby. [U. S.]
[1913 Webster +PJC]
3. (Naut.) An apartment or passageway in the fore part of an
old-fashioned cabin under the quarter-deck.
[1913 Webster]
4. (Agric.) A confined place for cattle, formed by hedges.
trees, or other fencing, near the farmyard.
[1913 Webster]
Lobby member, a lobbyist. [Humorous cant, U. S.]
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Lobby \Lob"by\, v. i. [imp. & p. p. Lobbied; p. pr. & vb. n.
Lobbying.]
To address or solicit members of a legislative body in the
lobby or elsewhere, with the purpose to influence their
votes; in an extended sense, to try to influence
decision-makers in any circumstance. [U.S.] --Bartlett.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Lobby \Lob"by\, v. t.
To urge the adoption or passage of by soliciting members of a
legislative body; as, to lobby a bill; -- also used with the
legislators as object; as, to lobby the state legislatuire
for protection. [U.S.]
[1913 Webster]