department, course, section
科 centers on classification into organized groups: a department, a course of study, or a section within a larger structure.
科 combines 禾 (grain) and 斗 (a measuring dipper), originally referring to measuring and sorting grain into categories. This idea of sorting extended to classification and departments.
Picture grain 禾 being measured with a dipper 斗 and sorted into different bins: each bin is a department or section.
For カ, imagine a course catalog where every department is listed under the letter 'Ka': Ka -> カ, like a section labeled 'Ka'.
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science
department (of a university or hospital)
surgery (branch of medicine)
textbook; coursebook; schoolbook
dentistry
subject (of study); course of study
(school) subject; curriculum; course
internal medicine
subject; curriculum
science (natural sciences and related fields, incl. mathematics, engineering, medicine, etc.)
humanities and social sciences; liberal arts
ophthalmology
pediatrics
maternity and gynaecology department (gynecology); department of obstetrics and gynaecology (gynecology)
engineering course
medical science; medical department
obstetrics
to inflict; to impose (a fine, etc.)
Science and Technology Agency (1956-2001)
humanities; arts
subcommittee; subworking group; breakout session
medical science
surgeon
gynecology department
home economics
orthopedic surgery; orthopaedic surgery; orthopedics; orthopaedics
Ministry of Education, Culture, Sports, Science and Technology; MEXT
dentist
dentist
dental hygienist
encyclopedia; encyclopaedia
dermatology
ophthalmologist; eye specialist
social studies (school subject)
social science
science and technology; technology; scientific techniques
scientific
scientist
psychiatry; psychiatric department
otolaryngology; ear, nose, and throat department
natural science
elective subject or course