Simple past tense and past participle of shadowbox.(verb)
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Use "shadowboxed" in a sentence
"Bells evoking a Buddhist temple are shadowboxed behind the register."
"Pieces of a stone frieze were hung along the left wall over three shadowboxed pieces of carved stone artwork and a gilded display case, softly lit."
"In Atlantic City he shadowboxed with the beat on " Just Like a Woman, " going silent when the crowd gamely sang the chorus, then rushing out the words himself."