"装聋作哑" is formed by juxtaposing two verb-object phrases: "装聋" (pretend deaf) and "作哑" (act mute), where 装 means "pretend", 聋 means "deaf", 作 means "act", and 哑 means "mute"; the combination directly illustrates the act of feigning ignorance through simultaneous pretense of deafness and muteness.