(sports, skateboarding, snowboarding, skiing) Clipping of 540. (540° spin)

That end of any DNA strand that has a terminal phosphate group.

(informal) Relatively close to the 5′ end of a strand of DNA.

(military) The planning section of an Air Force staff. / (military) Vigilante supersonic attack aircraft.

Luxurious and expensive.

(US, slang, street slang) The police.

(US) Interstate 5, an interstate highway running between Blaine, Washington and San Diego, California

plural of 5 percenter

A day job, especially at a large company, emphasizing banality. / The workday itself (the period of the day between 9 am and 5 pm). / One who works in a job from 9 am to 5 pm.

The neurotransmitter serotonin.