tubular
Shaped like a tube, long, round, and hollow.
Tubular means shaped like a tube: long, round, and hollow, like a pipe or a straw. A tunnel is tubular. So is a garden hose, a telescope, or the cardboard tube inside a roll of paper towels. Your body contains tubular structures too: blood vessels are tubular, carrying blood through your system like water through pipes.
In the 1980s and 90s, surfers and skateboarders started using tubular as slang meaning “awesome” or “excellent.” When a surfer rode through the curved, tunnel-like space inside a breaking wave (called “the tube”), it was the ultimate thrill, so “tubular” became their word for anything amazing. You might still hear someone jokingly say “Tubular, dude!” to mean “That's great!” though the slang sounds pretty dated now.
Engineers talk about tubular steel in bicycle frames. Botanists describe tubular flowers like honeysuckle, whose petals form a long tube that hummingbirds love. Whether you're describing the shape of pasta (like rigatoni, which is tubular) or the design of a musical instrument like a trumpet, tubular captures that distinctive hollow, cylinder shape.