Spondaic describes a line, phrase, or word pattern built around spondees-two strongly stressed syllables in a row. Poets use spondaic rhythm to slow the pace, add weight, or make a line feel forceful and heavy. It is usually a variation within a poem's meter, not a full meter by itself.
Example
The stones cracked
the road split
under black boots
An example from “In Memoriam” by Alfred Lord Tennyson
“When the blood creeps and the nerves prick”
Words
bread box, shoeshine