40 in a 30
it means UGLY, faced just fucked up, this would be due to running a 40 yard sprint in a 30 yard gym.
"OH SHIT, she did a 40 in a 30, thats a 40 yard sprint in a 30 yard gym, she hit that wall at full speed and got B-U-S-T-E-D!!!!!!!
40/30
Someone who is in their 40s but looks like they're in their 30s.
I met this super hot 40/30 last night. She's 44, but she looks like she's 32.