"One Word" is the first and only single from Kelly Osbourne's second album Sleeping in the Nothing. Unlike the pop/punk sound Osbourne sported in the past, "One Word" was a synthpop song that showed Osbourne embracing dance music. The single sounded very reminiscent of the 1980s Visage song "Fade to Grey", which caused some controversy over copyright issues, which was finally settled out of court when Osbourne's writing team agreed to give Visage a share of the royalties.
The song received a positive reaction from music fans and even some of Osbourne's harshest critics. On the track, Billboard said "she glides through the space-age number like she's the princess of the new wave dancefloor." Similarly, Malinda Lo said the track "eases you in with a spacey, synthesized intro" and "makes use of computer assistance in the best possible way". Brian Hiatt with Rolling Stone remarked, "Turns out her affectless vocals are better suited to...Eurythmics-biting synth-pop." While the single wasn't a hit on the US Hot 100, it was extremely successful in the US dance charts and was consistently played at nightclubs across the nation thanks in part to a remix by acclaimed DJ Chris Cox. In the UK, the original track reached #9.