Κ Kappa (cap-pah) Λ Lambda (lamb-dah) Μ Mu (mew) Ν Nu (new) Ξ Xi (zie or zee) Ο Omicron (om-e-cron) Π Pi (pie) Ρ Rho (roe) Σ Sigma (sig-mah) Τ Tau (taw) Υ Upsilon (youp-si-lon) Φ Phi (fie or fee) Χ ...

Some know “sigma” as the 18th letter of the Greek alphabet but it’s also teen slang for a cool dude. According to Know Your ...

Here is everything we know about what it all means. Thought it was the 18th letter of the Greek alphabet? You would be wrong.