Sentence:  That was many years ago, twenty years or more, and during this time Okonkwo's fame had grown like a bush-fire in the <WSD>harmattan</WSD>. 
Meaning of the word marked with <WSD> tags:  A dry and dusty wind which blows from the Sahara over the Atlantic coast of West Africa in December, January and February, being a hot wind in some areas and a cold wind in others.