Ostentatious means showy in a way that's meant to impress others or attract attention, often through displays of wealth, knowledge, or importance. When something is ostentatious, it's deliberately flashy, designed so that everyone will notice and be amazed.

An ostentatious mansion might have gold-plated fountains, marble columns at the entrance, and a fleet of expensive cars in the circular driveway. The owner wants everyone who drives by to see their wealth and be impressed by it. Someone wearing ostentatious jewelry might pile on multiple diamond necklaces and enormous rings, choosing pieces based on how much attention they'll attract rather than personal taste.

The word carries a hint of criticism. While there's nothing wrong with having nice things or being proud of achievements, ostentatious behavior feels excessive and attention-seeking. Compare someone quietly driving a nice car to someone revving their engine at every stoplight and parking across two spaces.

In school, an ostentatious student might constantly mention their test scores, wave graded papers around, or make sure everyone knows about every award they've won. The accomplishments are real, but the constant showing-off can make others uncomfortable.