잠을 설치다.

The phrase '잠을 설치다' (jam-eul seol-chi-da) is composed of two parts: '잠' (jam), meaning 'sleep,' and '설치다' (seol-chi-da). The verb '설치다' has several meanings, including 'to act rashly or carelessly,' 'to make a fuss or create a disturbance,' and in a more archaic or less common usage, it can imply something being 'scattered' or 'disordered.' In the context of sleep, '설치다' evokes the idea of sleep being disturbed, incomplete, or not settled. It suggests a night where sleep is not continuous or deep, but rather broken and restless, as if the sleep itself is 'making a fuss' or is 'disordered.' The exact historical linguistic development leading to this specific idiomatic meaning for '설치다' in combination with '잠' is not extensively documented in commonly accessible etymological sources. However, the existing meanings of '설치다' provide a strong metaphorical basis for understanding '잠을 설치다' as 'to disturb one's sleep' or 'to have one's sleep disturbed.' The 'disorder' or 'disturbance' aspect of '설치다' is key here. While a precise origin story dating back hundreds of years with specific textual evidence for this exact phrase might be elusive in short-form etymological entries, the construction aligns with common Korean linguistic patterns where verbs describing actions or states are combined with nouns to create nuanced expressions. The meaning is derived from the established semantic range of the component words, particularly '설치다' in its sense of disruption or agitation.