Sentence:  She was among a number of cadets taken to the infirmary with heat sickness on the first day of the rigorous drills called <WSD>hell week</WSD>. 
Meaning of the word marked with <WSD> tags:  The week during which new members are required to undergo undignified rites of initiation or gruelling discipline in order to be accepted into a fraternity, sorority, secret society, military group, etc.