mod (Adjective) — Relating to a recently developed fashion or style. ex. "their offices are in a mod skyscraper"
mod (Noun) — A British teenager or young adult in the 1960s; noted for their clothes consciousness and opposition to the rockers.
mod (Noun) — An integer that can be divided without remainder into the difference between two other integers.
mod (Noun) — The absolute value of a complex number.
mod (Verb) — Modify, esp. to change a program or device to do something different from its original function. ex. "it's the original game modded to run on modern computers under larger resolutions"