If you want to pursue Chaucer's vocabulary for medicine and healing, you should begin with his words for doctor--"physician" and "leech." A complete concordance to Chaucer's work is available in most university libraries. A concordance (we also note this in Labor, Link 2) lists every word in an author's texts and gives the complete line in which that word is used.
When you consult A Concordance to the Complete Works of Geoffrey Chaucer, compiled by John S. P. Tatlock and Arthur G. Kennedy (Washington, D.C., 1927), you will find, all instances of "leech" in the singular or plural, and complete lines in which the word is used to give you some idea of context. Check the beginning of the Concordance for the abbreviations for the texts.
You should also consult the in-progress Middle English Dictionary (in the Reference section) for these words.
Work such as we describe here is called "word field studies," a highly developed branch of language study. We are limited in the kinds of word studies we can undertake in SEAFARER at present because most texts in the program are dealt with in translation. But Middle English is far easier than Old English and far less an obstacle in this regard; therefore word studies are often used as the basis for assignments in Chaucer courses.
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