attacking or ignoring cherished beliefs and long-held traditions, etc., as being based on error, superstition, or lack of creativity: an iconoclastic architect whose buildings are like monumental sculptures.
2.
breaking or destroying images, especially those set up for religious veneration.
a person who attacks established or traditional concepts, principles, laws, etc
2.
a. a destroyer of religious images or sacred objects
b. an adherent of the heretical movement within the Greek Orthodox Church from 725 to 842 ad, which aimed at the destruction of icons and religious images
[C16: from Late Latin iconoclastes, from Late Greek eikonoklastes, from eikōn icon + klastēs breaker]