1. A colourless element that is one of the six inert gasses; occurs in trace amounts in air
   - krypton, Kr

Type of: argonon, chemical element, element, inert gas, noble gas

Part of: air

• positive
• positive charge
• positive chemotaxis
• positive correlation
• positive degree
• positive feedback
• positive fraud
• positive identification
• positive magnetic pole
• positive muon
• positive pole
• positive reinforcer
• positive reinforcing stimulus
• positive stimulus
• positively
• positively charged
• positiveness
• positivism
• positivist
• positivistic
• positivity
• positron
• positron emission tomography
• positron emission tomography scanner
• posology