Single Digit Midget 

Primarily used in the military to refer to someone who has been on an extended deployment and now has less than 10 days left before going home.

Only nine days left before I get home, I am a single digit midget!

Single Digit Midget by LogicalOperator July 2, 2008

Single-digit IQ 

Jokingly describing some one with narrow mind of the world, or have low understanding on everything, or some one with idiotic behaviors or mind. Single-digit refers to a number from 0 to 9.

The guy's got a single-digit IQ, he's full of crap.

Single-digit IQ by Shirley Lin June 26, 2006

single-digit-year-old 

a kid on the internet, can be used to refer to a kid in general

Kid: L Gay
Person 1: what the fuck
Person 2: don’t worry, he’s a single-digit-year-old.

single-digit-year-old by iJustWannaGoZzzzzz April 8, 2023

Single digit income

An income that's less than $ 10000 a year. What the major percentage of the United States working population earns for a living.

Your friend: Hey did you check out Rob's new ride? It's off the hook.
You: Yeah I did. What I can't figure out is how he can afford a brand new Cadillac with only a single digit income. You know he's a bagger at Wallmart, he must have something going on on the side.

Single digit income by Karma1 June 18, 2009