Free Online Rhyming Dictionary

Rhymer offers six types of rhymes:

1. End Rhymes (blue/shoe)
2. Last Syllable Rhymes (timber/harbor)
3. Double Rhymes (conviction/prediction)
4. Triple Rhymes (frightening/brightening)
5. Beginning Rhymes (physics/fizzle)
6. First Syllable Rhymes (carrot/caring)

http://www.rhymer.com/