"one versed in the nature or diagnosis of diseases," 1640s, from pathology + -ist.
Entries linking to pathologist
pathology n.
"science of diseases," 1610s, from French pathologie (16c.), from medical Latin pathologia "study of disease," from Greek pathos "suffering" (from PIE root *kwent(h)- "to suffer") + -logia "study" (see -logy). In reference to the study of abnormal mental conditions from 1842. Ancient Greek pathologia was "study of the passions;" the Greek word for "science of diseases" was pathologike ("pathologics").
-ist
word-forming element meaning "one who does or makes," also used to indicate adherence to a certain doctrine or custom, from French -iste and directly from Latin -ista (source also of Spanish, Portuguese, Italian -ista), from Greek agent-noun ending -istes, which is from -is-, ending of the stem of verbs in -izein, + agential suffix -tes.
Variant -ister (as in chorister, barrister) is from Old French -istre, on false analogy of ministre. Variant -ista is from Spanish, popularized in American English 1970s by names of Latin-American revolutionary movements.