1. A phaser is an electronic audio signal processor used to distort a signal by mixing a dry, or unprocessed, signal with copy of itself that has been filtered through an all-pass phase-shift network. As the filtered signal is mixed with the dry signal, the effect is that of a comb filter, notching out and reinforcing frequencies at fixed intervals up the frequency spectrum. When the all-pass filtered signal alone is heard at the output, the effect is commonly referred to as vibrato. In motion picture or television production, the effect is often used to imply that a sound originates from an artificial source (e.g. a computer or robot voice.)
2. Phasers are a weapon in the fictional series Star Trek.
