Sentence:  When he was bent over behind the wheel of the station wagon , feeling in his trouser cuffs for the ignition key which he had dropped a moment before , she came out of the house with an enormous Rumanian shawl over her head , which she had bought in that country during one of their trips abroad , and handed him a <WSD>clean</WSD> handkerchief through the window . 
Meaning of the word marked with <WSD> tags:  free from dirt or impurities; or having clean habits