grandiose
/ˈgran-dē-ˌōs/
adjective
characterized by affectation of grandeur or splendor or by absurd exaggeration
impressive because of uncommon largeness, scope, effect, or grandeur
They did not believe his grandiose claims.
grand magnificent imposing stately majestic grandiose mean large and impressive. grand adds to greatness of size the implications of handsomeness and dignity. magnificent implies an impressive largeness proportionate to scale without sacrifice of dignity or good taste.