indicating a person skilled or involved in a branch of study denoted by a noun ending in -logy (such as biologist corresponding to Biology).
-ologist means the person who studies.
The word 'dermatology', recorded in 1819, comes from the Greek derma, meaning skin, leather, or hide, plus the Greek suffix -logy, meaning science (of) or branch of learning or knowledge.The term 'dermatologist' comes into English from the same roots as above, with the suffix -logist, meaning practitioner of, or expert, or learned, in, added in 1861.
There are many suffixes that mean the person who. They include -ant, -aholic, -an/ian, -ar, -ard, -arian, -er, -ist, -loger/logist, -or, -path, -phile, and -plegic.
Podologist pod/o- (Foot) -logist (one who studies)
Other than saying the person is a "specialist in..." or a "... major" (if in college), there's the use of the suffix "-logist" or "-ologist" for experts/scholars in particular fields: antropologist, paleontologist, mineralogist, theologist, meteorologist, biologist, bacteriologist... "TheEnglish suffix -ology or -logydenotes a field of study or academicdiscipline, and -ologist describes a person who studies that field. (source: http://en.wikipedia.org/wiki/List_of_ologies#List_of_-ologies)
A person who specializes in a particular field of science or study.
M. S. Wingersky has written: 'Logist user's guide'
Anthropologist Anthr/o- (Man) -logist (One who specializes in the study or treatment of)
Neglectful combines "neglect" with the suffix "-ful".
The suffix for undo is to not do.