Technically a proper name - the first “r” in “Worcestershire” (sauce).
I don’t believe there are any words that start with pt where the p is pronounced.
Ptosis, ptomaine, ptisan, pterin…I’m sure there are others.
Except, perhaps, ptooey. 
mmm
I always assumed that if you spelled it with an o, you’d pronounce the o, but it appears that some people do in fact consider the o silent.
I thought of this because of the movie, “Johnny Mnemonic”
mne·mon·ic
/nəˈmänik/
That’s one that I keep forgetting.
A Roger Moore movie: “ffolkes.”
Ctenophore and cnidarian are fun biology class examples for a silent C.
Lot’s of good answers here. I especially liked pterodactyl.
But no silent v. I guess Jim was right. Jim’s real name was Joachim, but always called himself Jim so I guess the oach was silent.
Lots and lots of silent letters in “forecastle”.
Almost as many in “botswain.”
Not only are there no silent Vs, but AFICT, there’s only one instance where there’s a V-sound which is not spelled with a V. That occurs in one of the most common words in English: of.
I pronounce it as spelled.
My friend - a tall ship sailor - pronounces it the pirate way: fo’c’sle
The best I can do is the word “voila,” which apparently a lot of people pronounce with a silent V–hence spelling it “walla” or similar.
That’s not really a silent V. Just pronouncing the V as /w/ instead of /v/. It’s much the same as many words spelled with an S where that letter is pronounced /z/ instead of /s/.
I disagree. The word “voila” comes from French, and in French “oi” makes a “wah” sound (e.g. au revoir). So the /w/ is already in the word.
Normally, I’d say that English is not French, so how it’s pronounced in French is irrelevant. But there are a few other words from French with ‘oi’ that we pronounce with a /w/, so I guess I’ll concede the point.
This reminds me of one of my favorite pronunciation trivia questions, one which I came up with myself and have never seen elsewhere.
The /kw/ sound in English is usually spelled QU, however, there’s one or two words where it’s spelled KW. What English word has a /kw/ sound but does not have a Q, U, K or W anywhere in the word? Note: this is not an obscure word found only in unabridged dictionaries.
Choir?
Yep, you got it.
Nice. I thought of “coif” but I wasn’t sure whether that counted as an English word.
M-W has that word with two different pronunciations. One has a /kw/ sound, but I don’t use that pronunciation.