Sentence:  Was it a case of <WSD>spring fever</WSD>, or just a horse longing for its stable? Whatever the reason, one of the city's normally well-disciplined police horses bolted yesterday, injuring its rider and leading several patrol cars on a milelong chase through Lower Manhattan. 
Meaning of the word marked with <WSD> tags:  A feeling of invigoration and restlessness associated with the arrival of the warm weather and renewal of nature in the spring season.