Sentence:  John Betjeman would later recall that the railway 'smelt of feet', and the carriages may have continued to smell of feet after they were taken out of service in the 1920s because some of them found use as <WSD>changing rooms</WSD> beside the playing fields of southern England. 
Meaning of the word marked with <WSD> tags:  A room, especially in a gym, designed for people to change their clothes.