Green’s Dictionary of Slang

-spot sfx

[the number of pips on a playing-card was described in this way]

1. [mid-19C; 20C+] (orig. US) a term of imprisonment, usu. one year; thus usu. preceded by the number of years.

2. [mid-19C+] a dollar, a pound, as a denomination of a note; in combs. below; note also spot n.2

In phrases

five-spot (n.)

1. [late 19C+] (also V-spot) a $5 or £5 note.

2. [1900s–60s] (US) a five-year prison sentence.

3. [1910s] (US) a five-dollar gold piece.

4. [1980s] (N.Z.) NZ$500.

one-spot (n.)

1. [late 19C+] (US) a $1 bill.

2. [20C+] (US Und., also one-spot sleep) a one-year prison sentence.

3. [1990s+] (Aus. drugs) A$100 worth of heroin.

ten-spot (n.)

1. [mid-19C+] (US) a $10 bill or £10 note.

2. [1900s] (US campus, also ten-strike) a perfect recitation [f. sense 1, but also the idea of ten out of ten].

3. [1900s–60s] (US prison) a ten-year prison sentence.

twenty-spot (n.)

[mid-19C+] a £20 note or $20 bill.

two-spot (n.)

1. [mid-19C+] (US) a $2 bill.

2. [late 19C–1930s] any low-value playing card.

3. [late 19C–1930s] thus in fig. use, an insignificant person.

4. [1900s–40s] (US prison/Und., also two-spotter) a two-year sentence.

5. [1970s–80s] (Aus. Und.) A$200.

6. [1990s+] (Aus. drugs) A$200 worth of heroin.

SE in slang uses

In phrases

nine-spot (n.) [card imagery: the relative low ranking of nine, compared to the court cards]

[late 19C–1900s] (US) a nonentity.