What rhymes with could - 1 syllable
 good
 goode
 hood
 schuld
 should
 stood
 wood
 would
 you'd

What rhymes with could - 2 syllable
 fulwood
 suhud
 withstood

What rhymes with could - 3 syllable
 understood

What rhymes with could - 4 syllable
 misunderstood