Dip-thong

[Rudolph C Troike]

Unlike Larry, whenever and wherever I first picked up the word, it was
solely with /p/, and I suspect that I probably even spelled it that way
until forced by comparison with "monoph-thong" to notice the -ph- . Unless
I am being very careful in lecture, I usually still pronounce it with /p/.
        Similarly, I learned "amphitheater" with /p/ as well, and it was
not until I was living in Turkey and discovered that it was written with
-f- that I noticed the -ph- in the spelling. Interesting that M-W 10th
also gives the pronunciation with -p- as second, indicating that in both
cases it must be fairly common.
        I suspect that there must be a connection between these two,
neither of which has anything to do with the rampant folk-etymologizing
(are linguists "folk"?) on this list. Given the learned nature of both
words, they are not routinely collected in Linguistic Atlas interviews, so
there is probably no regional-distribution information available. --Rudy