The word 噎住 is formed by combining 噎, meaning 'to choke,' which itself incorporates the mouth radical 口 for semantic relation to the throat and 壹 for phonetic indication, with 住, meaning 'to stop.' Here, 住 functions as a resultative complement attached to 噎 to denote the state resulting from choking, thus together conveying the meaning of being choked or having something obstruct the throat.