-ology
-ology means study of

anthropology (n) - the study of humans

biology (n) - the study of life and living things

cardiology (n) - the study of the heart

dermatology (n) - the study of the skin

ecology (n) - the study of the environment

geology (n) - the study of the physical nature, structure, and history of the earth

graphology (n) - the study of handwriting and how it relates to a person's character

psychology (n) - the study of the mind

sociology (n) - the study of how people interact

zoology (n) - the study of animals