In linguistics, cognates are words that have a common etymological origin.
The term derives from the Latin cognatus (blood relative). In linguistic research it is generally understood as excluding doublets and loan words, although broader definitions are used in other areas such as language teaching.
Cognates do not need to have the same meaning, which may have changed as the languages developed separately. For example, consider English starve and Dutch sterven or German sterben ("to die"); these three words all derive from the same Proto-Germanic root, *sterbaną ("die"). English dish and German Tisch ("table"), with their flat surfaces, both come from Latin discus, but it would be a mistake to identify their later meanings as the same. Discus is from Greek δίσκος (from the verb δικεῖν "to throw"). A later and separate English reflex of discus, probably through medieval Latin desca, is desk (see OED s.v. desk).
Cognates also do not need to have obviously similar forms: e.g., English father, French père, and Armenian հայր (hayr) all descend directly from Proto-Indo-European *ph₂tḗr.
When summers are forgotten
And brothers slay each other
When the legions of Surt rise
And Muspell´s horde fills the skies
When the Norns annihilate all peace
And Naglfar sails the seas
The dawn of the final war is here
When gods wage war the end is near
When the horn of Heimdall blows
And holy blood in thick rivers flows
When the son of Loki breaks his chains
And Midgard is consumed by flames
When forces of darkness and light collide
For puny mortals there´ll be nowhere to hide
The dawn of the final war is here
When gods wage war the end is near
When the raven flies
We must heed the call
When the raven flies
We will stand or fall
When the raven flies
We must heed the call
When the raven flies
We will stand or fall
When the sky turns black as night
And nothing is left but the will to fight
When the Einherjar are to fulfill their destiny
There´s no more use for All-Father's necromancy
When giants and trolls united ride
And even Wodan and Donar fall side by side
The dawn of the final war is near
When gods wage war the end is here