Perfect Rhymes (Same vowel sound and ending):
* None - There aren't many words that perfectly rhyme with "spammer".
Near Rhymes (Similar vowel sound, but different ending):
* hammer
* jammer
* stammer
Eye Rhymes (Spelled similarly but pronounced differently):
* streamer
* summer
* rummer (an archaic word for a drinking cup)
Words with Similar Meaning:
* shiller (someone who promotes something dishonestly)
* hustler (someone who tries to trick others)
* phisher (someone who attempts to obtain personal information)
Ultimately, the best rhyme for "spammer" depends on the context of your poem or writing.