1. （艺术、音乐、戏剧、文学）先锋派的，前卫的，实验性的
Avant-garde art, music, theatre, and literature is very modern and experimental.

2. 先锋派；前卫派
You can refer to the artists, writers, and musicians who introduce new and very modern ideas as the avant-garde .

1. any creative group active in the innovation and application of new concepts and techniques in a given field (especially in the arts)

Synonym: vanguardvannew wave