Welcome to Gaia! ::

No rush 20 min? Er...

And why no mm when you don't know what it is? I hope you mean MM as in M&M. Or Marines and Medics.

MM is a term used in moneymaps that stands for Map Maxed.

Map Maxed means that the sprite limit on the map has been reached. No other sprites will be created, and therefore no more units or buildings can be made unless they are converted.
Examples would be converting a Geyser to a Refinery, since the Geyser sprite is converted to a Refinery, this will be allowed if map is maxed. If a Drone is converted to a Hatchery, this will also be allowed.

Luckily units can still shoot in Map Max. If enough units are shooting projectiles at the same time, it'll just shut down the attack overall. [like in those evolves maps when units eventually stop shooting]