Green’s Dictionary of Slang

1. a watch-house.

c.1786		Grose Classical Dict. of the Vulgar Tongue ms. additions n.p.: Light House, A Watch House.
1821		Egan Life in London (1869) 113: I [...] must have foundered had it not been for the assistance of a pilot, who safely towed me into the light-house.
1938		R. Hyde Nor the Years Condemn 185: He had a job attending the ‘lighthouse’ at the Napier Gaol.

2. an especially prominent nose, esp. when reddened by years of drinking; a person with such a nose.

1811		Lex. Balatronicum n.p.: Light House. A man with a red fiery nose.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue [as cit. 1811].
1859		Matsell Vocabulum.
1895		C. Crowe Aus. Sl. Dict. 45: Light-house, a red nose.

3. a lookout man.

1899		J. Flynt Tramping with Tramps 386: ‘Lighthouse’ [...] means a man who knows every detective of a town by sight, and can ‘tip them off’ to visiting hoboes and criminals.
1901		J. Flynt World of Graft 193: Some become tramps, perhaps the majority; others develop into small gamblers, billiard markers, and ‘lighthouses’ (look-outs) for ‘cribs’ (gambling joints).
1921		P. & T. Casey Gay-cat 303: Lighthouse — one well-acquainted with the police and detectives and can give warning when they are near, to his pals.
1930		‘Dean Stiff’ Milk and Honey Route 209: Lighthouse – Stingy person. [...] Also one who is placed to watch for the bulls.
1949		Monteleone Criminal Sl. (rev. edn).
1963		L.F. Freed Crime in S. Afr. 106: A ‘lighthouse’ is one who has a knack of spotting any detective.
1979		K. Bonfiglioli After You with the Pistol (1991) 332: Every [...] professional team of thieves has a [...] ‘lighthouse’. [...] He has but one simple, God-given skill: he can recognize ‘fuzz’, ‘filth’, ‘Old Bill’ or any other form of copper, however plainly-clothed.

4. (US tramp) a knowledgable individual, esp. of which policemen are to be avoided in a given town.

1900

Nat. Police Gaz. (NY) 30 June 6/1: He is the best lighthouse in Hoboland [...] a lighthouse is a man who knows the dangerous detectives and policemen and can tip his pals whenever they are around.

5. (N.Z.) an illicit dealer in alcohol who carries supplies around and canvasses potential customers.

1908		Truth (Wellington) 8 Aug. 1: The ‘lighthouse’ so familiar in prohibited districts is becoming quite common in Christchurch [DNZE].
1910		Truth (Wellington) 15 Jan. 5: The illicit dealer in shypoo and chain-lightning sets himself up as a ‘lighthouse’... The ‘light-house’, in short, is an individual who carries round a bottle with him and personally canvasses customers [DNZE].

6. (US Und.) those members of a safecracking team who wait outside while the ‘parlor man’ lights the fuse to the explosive.

1914

Wash. Post 11 Nov. Miscellany 3/6: The members of the gang who remain outside are the ‘lighthouses.’.

7. (US Und.) a lookout man or a person who procures customers for a brothel.

1913		G.J. Kneeland Commercialized Prostitution in N.Y. City 6: A porter is employed to care for the house [...] a ‘lighthouse,’ to stand on the street for the purpose of procuring ‘trade’ and to give warning.
1930		‘Dean Stiff’ Milk and Honey Route 209: Lighthouse – [...] A procurer for a house of sin.
1949		Monteleone Criminal Sl. (rev. edn).