Abstaining from alchohol,drugs, and casual sex. This definition comes from a song sung by the underground 80's punk band minor threat from Washington D.C. whose lead singer Ian Mckaye sang about how abstaining from aforementioned things was cool and gave you an edge up on drug users and alchoholics.
The kids didn't drink at the party because they are straitedge.
another term for a station wagon, mini-van, or any other kind of vehicle that is targeted at the "family" demographic(also M.A.V.)
"Tactical advantages aside, the M.A.V. is top of the line for the holy warrior troop transport manufactured by the Church of Latter Day Saints Military Industrial Complex. Also great for family trips...to heathen lands."