1. Occurring ever half hour

1. Every thirty minutes, every half hour

See also: periodic, periodical

• shadbush
• shaddock
• shade
• shade off
• shade tree
• shaded
• shader
• shades
• shades of
• shadflower
• shadfly
• shadily
• shadiness
• shading
• shadoof
• shadow
• shadow cabinet
• shadow play
• shadow show
• shadowbox
• shadowboxing
• shadowed
• shadower
• shadowgraph
• shadowiness