1 1.0 is normal speed, 0 is stopped, numbers between 0 and 1.0 are slower playback, negative numbers are rewind and numbers higher than 1.0 are faster playback.  The forward and backward buttons to the right of Play speed are for moving videos frame by frame.
Slow Food Movement. An international movement begun by Carlo Petrini with a forerunner organisation, Arcigola, founded in 1986 to resist the opening of a McDonald's (fast food restaurant) near the Spanish Steps in Rome.
For the spell used by mages, see Slow (mage). Slow is a general term for any effect (debuff) that lowers the target's attack or movement speed. Some slow effects have specific names like daze and chill.