Logy is defined as a particular branch or field. An example of logy used as a suffix is in the word biology, the study of living matter.

What does logy mean?

: sluggish, groggy. Examples: I was feeling logy after eating such a big meal, so I decided to take a brief nap.

What does the Latin suffix logy mean?

Wiktionary. -logysuffix. A branch of learning; a study of a particular subject. Examples: biology, geology, genealogy. Etymology: The English -logy suffix originates with loanwords from the Greek, usually via Latin and French, where the suffix is an integral part of the word loaned.