Symbol
A symbol is something that represents more than itself. In Baywolf, the meat hall, hero, symbolizes, community, civilization and order. when Grendel attacks it, he threatens those very concepts. 
Epithet
An epithet is a descriptive phrase, expressing a quality or characteristic of the person or thing mentioned 
Caesura
A Cezara is a pause in a line of poetry often marked by punctuation or natural speech rhythm. Old English poetry frequently uses it.
Kenning
A Kenning is a figurative compound expression used in a place of a more straightforward noun.
Alliteration
Alliteration is the repetition of an initial consonant sounds in nearby words. It is a central feature of old English poetry.
Consonance
Consonants is the repetition of constant sounds typically at the end or in the middle of words
Assonance
Assonance is the repetition of vowel sounds in nearby words