adjective
grandiose
GRAN-dee-ohs/ˈɡrændiəʊs/
Impressively grand or ambitious, often to an excessive or pretentious degree.
His grandiose palace model dwarfs the small available building plot.

Etymology
French grandiose emphasizes being impressive or grand in effect. Applied to plans or ambitions, that imposing scale can invite criticism rather than admiration when it seems showy or unrealistic.
In context
the ability to manage the mass distribution of resources and organized labor allowed the Egyptians to build grandiose structures including the pyramids
More examples
- The hotel entrance is grandiose but poorly maintained.
- She makes grandiose promises without explaining how to fulfill them.
- The modest event hardly needs such grandiose decorations.
Forms
grandiose · more grandiose · most grandiose