Green’s Dictionary of Slang

1. a blow, a slap.

1821–6

‘Bill Truck’ Man o’ War’s Man (1843) 396: ‘Chear up my soul!’ cried I, tipping the crest-fallen Jack a smacker ’twixt the shoulders.

2. a kiss.

1835		Morning Herald (NY) 5 Aug. 2/3: I longed for one sweet kiss. (What a smacker you gave me last night? O crikey how luscious.).
1989		M. Amis London Fields 187: What about a kiss for Keith? What about a smacker for the kisser of Keith Talent?
2000		Guardian G2 4 Apr. 4: Phil planted the welcome-home smacker at an ungodly 5am.
2013		T. Black Ringer [ebook] n.p.: It runs to me and throws arms round me, plants a big smacker on my lips.

3. (Aus.) a girlfriend [? play on sense 1].

1914

Sport (Adelaide) 31 Jan. 4/1: Poor old Reggie B. is [...] broken-hearted because he has lost his little smacker.

4. (US) a boxer.

1929		H.C. Witwer Yes Man’s Land 232: I carried a bruise where this priceless dwarf landed on me [...] the kid was one tasty smacker.
1930		Queenslander (Brisbane) 10 Jan. 10/5: In his day ‘Smacker’ McCarthy had been a ‘goer’.

5. (US Und.) a year.

1950

Goldin et al. DAUL 199/1: Smacker. [...] 2. (P) A year.

6. (Aus.) a boy, a young man.

1951		D. Stivens Jimmy Brockett 13: I came back and spoke to the boy. ‘What’s the manager’s name here, smacker?’.
1988		McGill Dict. of Kiwi Sl. 104/2: smacker a lad, who may be smacked.
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].

7. (N.Z.) the mouth.

1988		McGill Dict. of Kiwi Sl. 104/2: smacker mouth, perhaps by association with smacking of lips.
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].

8. see smackers n.