Nibelungenlied is a poem from around 1200 written in Middle High German, so I believe "kenning" is the term for the archaic combinations of phrases in literature like this and Beowulf. Here's some reference text:
"kennings – compound expressions in Old English and Old Norse poetry with metaphorical meanings... Kennings are a traditional Norse poetic form where a group of words takes the place of the noun. They are normally used for repetition, imagery, and oral poetic diction. [In "The Prose Edda"] Snorri [an early norse scholar of poetry and prose] extracts the traditional kennings from their verses and weaves them into his own structured poetry, while prescriptively categorizing kennings by three usages. Snorri explains, “There are simple kennings, second double, third extended. It is a kenning to call battle ‘spear-clash’, it is a double kenning to call a sword ‘fire of the spear-clash’” (168). His verse makes use of kennings such as, “The splendid hater of the fire of the sea”, meaning: ‘a generous king’, or one who hates gold, so gives it away. In effect, the verse makes use of multiple simple and double kennings to create a single extended kenning that means: a good king keeps and defends his land (Brown 113).
Example Text Reference:
The splendid hater of the fire of the sea himself of gold, defends the beloved of the enemy of the wolf: ship’s prows are set before the steep brows of Mim’s friend’s wife. The noble mighty-ruler knows how to hold the serpent’s attacker’s mother. You who torments necklaces, enjoy the troll-wife’s enemy’s mother until old age. (168)
Hope this helps!