Ancient Greek word root · Speech & Writing

log-: word, speech, reason

log- is an Ancient Greek root meaning “word, speech, reason”. Learn its variants and explore 60 connected words.

Meaning and variants

Meaning: word, speech, reason

Root forms: log-, -logy, -logue, logo-

Source word: λόγος — that which is said: word, sentence, speech, story, debate, utterance, argument

Word family and examples

• technology

  the application of scientific knowledge for practical purposes

• psychology

  the scientific study of the human mind and its functions

• dialogue

  a conversation between two or more people

• biology

  the study of living organisms

• apology

  An expression of remorse or regret for having said or done something that harmed another: an instance of apologizing (saying that one is sorry).

• ideology

  Doctrine, philosophy, body of beliefs or principles belonging to an individual or group.

• theology

  the study of the nature of God and religious belief

• catalogue

  a complete list of items arranged systematically

• trilogy

  A set of three connected works—usually dramas, literary pieces, films, or musical compositions—all related by theme, characters, or setting.

• sociology

  A social science that studies society, human social interaction, patterns of social relationships, and the interactions of culture. Through both theory and applied research, it engages subject matters across a range of microanalysis, mesoanalysis, and macroanalysis.

• geology

  the science of the earth's physical structure and substance

• ecology

  The branch of biology dealing with the relationships of organisms with their environment and with each other.

• analog

  In which the value of a data item (such as time) is represented by a continuous(ly) variable physical quantity that can be measured (such as the shadow of a sundial).

• anthropology

  the study of human societies, cultures, and their development

• mythology

  The collection of myths of a people, concerning the origin of the people, history, deities, ancestors and heroes.

• physiology

  the branch of biology dealing with the functions of living organisms

• pathology

  the science of the causes and effects of diseases

• archaeology

  the study of human history through excavation and analysis of remains

• anthology

  A collection of literary works, such as poems or short stories, especially a collection from various authors.

• dialog

  Uncommon spelling of dialogue.

• morphology

  A scientific study of form and structure, usually without regard to function. Especially:

• astrology

  Divination about human affairs or natural phenomena from the relative positions of celestial bodies.

• oncology

  The branch of medicine concerned with tumors, including study of their development, diagnosis, treatment, and prevention.

• genealogy

  a line of descent traced from an ancestor

• epidemiology

  The branch of science dealing with the spread and control of diseases, viruses, concepts etc. throughout populations or systems.

• analogue

  Alternative spelling of analog.

• monologue

  a long speech by one actor or person

• neurology

  The branch of medicine that deals with the disorders of nervous system including the brain and spinal cord of the central nervous system and the nerves, muscles, and neuromuscular junction of the peripheral nervous system.

• prologue

  A speech or section used as an introduction, especially to a play or novel.

• chronology

  the arrangement of events in the order of their occurrence

• topology

  The branch of mathematics dealing with those properties of a geometrical object (of arbitrary dimensionality) that are unchanged by continuous deformations (such as stretching, bending, etc., without tearing or gluing).

• zoology

  the scientific study of animals

• toxicology

  The branch of pharmacology that deals with the nature, effect, detection and treatment of poisons and poisoning.

• epilogue

  a section at the end of a book that comments on what has happened

• cardiology

  the branch of medicine dealing with the heart

• cosmology

  the science of the origin and development of the universe

• ontology

  The branch of metaphysics that addresses the nature or essential characteristics of being and of things that exist; the study of being qua being.

• dermatology

  the branch of medicine dealing with the skin

• entomology

  The scientific study of insects, and (informal) of other arthropods (and occasionally other invertebrates).

• paleontology

  the study of fossil animals and plants

• archeology

  Uncommon spelling of archaeology.

• mineralogy

  The branch of petrology that studies minerals.

• phenomenology

  The study of structures of consciousness as experienced from the first-person point of view.

• homology

  The relationship of being homologous; a homologous relationship.

• phonology

  The study of the way sounds function in languages, including accent, intonation, phonemes, stress, and syllable structure, and which sounds are distinctive units within a language; (countable) the way sounds function within a given language; a phonological system.

• hematology

  The scientific study of blood and blood-producing organs.

• etiology

  US standard spelling of aetiology.

• ornithology

  The branch of zoology that deals with the scientific study of birds.

• travelogue

  A description of someone's travels, given in the form of narrative, public lecture, slide show or motion picture.

• numerology

  The study of the purported mystical relationship between numbers (or the letters of words, represented by numbers) and the character or action of physical objects and living beings.

• ideologue

  A person who advocates an ideology, especially as an official or preeminent advocate.

• tautology

  Redundant use of words, a pleonasm, an unnecessary and tedious repetition.

• mycology

  The study of fungi.

• demonology

  The study of demons, especially the incantations required to summon and control them.

• rheology

  The branch of physics that studies the deformation and flow of matter.

• ethology

  The scientific study of animalian behavior, especially that of nonhuman animals.

• homolog

  Something homologous; a homologous organ or part, chemical compound, chromosome, gene, or cultural element.

• ecclesiology

  The branch of theology concerned with the doctrines, role etc. of a church.

• cryptology

  The science or study of mathematical, linguistic, and other coding patterns and histories.

• neologism

  a newly coined word or expression

Root connections help with vocabulary recall. They are not a complete etymological history, and a spelling match alone does not prove a relationship.

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