The word "闪烁其词" is formed by combining the verb "闪烁" (meaning to flicker or shimmer) with the object phrase "其词" (meaning "its words"). The literal construction directly links the concept of flickering light to speech, creating a metaphorical idiom where evasive or ambiguous language is likened to the unstable and elusive quality of a flicker, thus describing someone who is deliberately vague in their expression.