What does HSS stand for on stratacaster guitar?

HSS stands for Humbucker-Single-Single. It refers to the configuration of pickups on a Stratocaster-style electric guitar. In this configuration, the guitar has a humbucker pickup in the bridge position, and single-coil pickups in the middle and neck positions. This pickup configuration offers the versatility of having the warm, thick sound of the humbucker for heavier or distorted tones, and the brighter, twangier sound of the single-coil pickups for cleaner or funkier tones.