Sentence:  the heat of <WSD>summer</WSD> 
Meaning of the word marked with <WSD> tags:  One of four seasons, traditionally the second, marked by the longest and typically hottest days of the year due to the inclination of the Earth and thermal lag. Typically regarded as being from June 21 to September 22 or 23 in parts of the USA, the months of June, July and August in the United Kingdom and the months of December, January and February in the Southern Hemisphere.