what rhyms with Vietnam?

Answer 1

Since the accent is on the LAST syllable, that's the ONLY one you need to match for a "perfect rhyme". So ANYTHING that ends with an accented /ahm/ sound will work

Try:

* balm, bomb, calm, com, mom, palm, prom, psalm, tom
(and a number of proper names, such as - Guam, Islam, Surinam)

Not perfect, but nearly as good, are words ending with /on/ (since the /m/ and /n/ sounds are very close):

* con, don, john, on, salon, swan, wan (Iran)

And, if none of those will work, you can probably get away with these in which you can barely hear the final added /d/:

* beyond, blond(e), bond, fond, frond, pond, respond, wand

__________________

Now, someone has noted another pronunciation of "Vietnam". In fact, the ending with the /ahm/ sound is still the MAIN one, in the US as well, so I recommend sticking with that.

But if for some reason you really want to match the secondary pronunciation which ends sounding like "am", you could use these:
*am, cam, clam, cram, dam, damn, dram, exam, gram, graham, ham, jam, jamb, lamb, pram, ram, sham, slam, spam, swam, tam. wham

Or, again, words ending with /an/ may do as well:
* ban, began, bran, can, clan, fan, man, pan, plan, ran, scan, span, tan (Japan, Sudan)

Also, once again, you can probably get away with something like:
* band, bland, brand, command, demand, expand, gland, grand, hand, land, sand, stand, strand, understand

Answer 2

Please note: This is not an opinion, criticism, a ridicule or anything of that sort. This just came to my mind.
Vietnam: quiet Sam. (People in the U.S. pronounce nam as nahm while others pronounce it as nam as in ham).

Answer 3

Drop a bomb kind of rhymes.

Answer 4

drop a bomb...

hot mom...

dot com...

Answer 5

See it, mom?