Definition from Wiktionary, the free dictionary
cognate (not comparable)
- Allied by blood; kindred by birth; specifically (law) related on the mother's side.
- Of the same or a similar nature; of the same family; proceeding from the same stock or root; allied; kindred.
- (linguistics) Either descended from the same attested source lexeme of ancestor language, or held on the grounds of the methods of historical linguistics to be regular reflexes of the unattested, reconstructed form of proto-language.
- English mother is cognate to Greek μητέρα (mētéra), German Mutter, Russian мать (mat’) and Persian مادر (madar).
- In English, queen is cognate to quean, both of which are cognate to Russian жена (žená), Icelandic kona and Irish bean.
- In English, shirt is cognate to skirt, both descended from the Proto-Indo-European word *sker-, meaning "to cut".
derived from the same roots
Derived terms 
cognate (plural cognates)
- One of a number of things allied in origin or nature.
- (law, dated) One who is related to another on the female side.
- (law, dated) One who is related to another, both having descended from a common ancestor through legal marriages.
- A word either descended from the same base word of the same ancestor language as the given word, or strongly believed to be a regular reflex of the same reconstructed root of proto-language as the given word.
word derived from the same roots as a given word
Derived terms 
See also 
- Plural form of cognata
- vocative masculine singular of cognātus