The article describes the primary cognitive signs of the grandmother concept in Russian linguistic culture. This concept received almost no comprehensive studies in modern linguistic literature. The research objective was to structure its motivating signs in their correlation with Russian myths and symbols. The research relied on eleven Etymological Dictionaries of the Contemporary and Old Russian Language. The obtained material was generalized and illustrated based on etymological, descriptive, interpretive, and conceptual analyses. The author revealed 46 motivating signs represented by 14 subgroups: 1. Ancient sacred symbols (seven signs): (water) spirit, (female) mythological character, stone idol / idol on ancient mounds, Pleiades (constellation), ancestor, sheaf, block / post / stump. 2. Woman (five signs): (female) sex, woman / wife, nurse, to assist in childbirth, to give birth. 3. Social status (five signs): witch, sorceress, healer, midwife, matriarch. 4. Relationship (five signs): to be pregnant, to be married, grandfather's wife, mother's / father's mother, relationship. 5. Game (three signs): playing blind man's bluff, dice, children's toy. 6. Inner world (one sign): soul. 7. Object of the natural world (eight signs): atmospheric object, butterfly / moth / insect, bud, cornflower, (unfolded) flower, bird (pelican), muddler / goby fish, oak-apple. 8. Age (two signs): elderly, old / old woman. 9. Status (two signs): headdress (married women), plait (around the head of a married woman). 10. Subject (three signs): tool for driving in piles; stand; bench. 11. Assessment (two signs): pet form, of low birth. 12. Part of animal's body (one sign): hoof bone. 13. Bread (one sign): bakery product. 14. Illness (one sign): smallpox. All signs in subgroups woman, game, age, assessment, animal body part, bread, and illness proved to be cognitive. Almost all signs in the remaining subgroups also proved cognitive, with several exceptions: ancient sacral symbols (block / post / stump), social status (healer), kinship (married), objects of the natural world (atmospheric object, bud), status (headdress of a married woman).