- 1[only before noun] directed or moving upward an up stroke the up escalator
- 2 [not before noun] (informal) cheerful; happy or excited The mood here is really up.
- 3[not before noun] having your turn at something; taking its place in the order of things Are you ready? You're up next. First up, a report on baseball's bright new star Stephen Strasburg.
- 4[not before noun] (of a computer system) working Our system should be up by this afternoon.