Sentence:  I sent my servant to the apothecary for a thing called an <WSD>ægrotat</WSD>, which I understood, for I never saw one, meant a certificate that I was indisposed, and that it would be injurious to my health to attend chapel, or hall, or lectures. This was forwarded to the college authorities. 
Meaning of the word marked with <WSD> tags:  A certificate indicating that a student is ill, excusing attendance at lectures and examinations and allowing courses to be passed without finishing the work.