Lobby
mid 16th century (in the sense ‘monastic cloister’): from medieval Latin lobia, lobium ‘covered walk, portico’. The verb sense (originally US) derives from the practice of frequenting the lobby of a house of legislature to influence its members into supporting a cause.
wiktionary
From Old French *lobie, from Medieval Latin lobium, lobia, laubia(“a portico, covered way, gallery”), borrowed from Frankish *laubijā(“arbour, shelter”), from Proto-Indo-European *lewbʰ-(“to break off, peel, damage”). Related to Old English lēaf(“foliage”). More at leaf. Doublet of loggia
Political sense derives from the entrance hall of legislatures, where people traditionally tried to influence legislators because it was the most convenient place to meet them.
lobby ( uncountable)
etymonline
lobby (n.)
1550s, "cloister, covered walk," from Medieval Latin laubia, lobia "covered walk in a monastery," from a Germanic source (compare Old High German louba "hall, roof;" see lodge (n.)).
Meaning "large entrance hall in a public building" is from 1590s; in reference to the House of Commons from 1630s. Political sense of "those who seek to influence legislation" is attested by 1790s in American English, in reference to the custom of influence-seekers gathering in the large entrance-halls outside legislative chambers.
lobby (v.)
"seek to influence legislation" (originally by frequenting the lobby of a legislature, to solicit members), 1826, American English, from lobby (n.) in the political sense. Related: Lobbied; lobbying.
