An event where guys significantly outnumber girls. This isn't great if you're a guy, and is especially not so great if you're an arsehole, as generally this means that your chance of pulling is, well, diminished.

a party or other function where males overwhelmingly outnumber females

An event where there are way more dicks than chicks present.

Rochester Institute of Technology.

A group of 5 or more that consists of 80%-100% males. Refers to the amount of "sausages" in the group.

Hidden agenda where most guys hang out for social purposes
It usually invovles computers and an overwhelming number of boys and few girls (if any, excluding the mothers)

a big asss party full of penis and few girls