The association between vowelindromes and the female breast, noted by Stephen Chism in the August 1993 Word Ways, is even more widespread than he realizes. Besides PAP and TIT, both part of the vowelindromes PAP-PEP-PIP-POP-PUP and TAT-TET-TIT-TOT-TUT, there exist BUB (a woman's breast) and DUD (a teat). The words in the corresponding vowelindromes BAB-BEB-BIB-BOB-BUB can all be found in the Oxford English Dictionary, and DAD-DED-DID-DOD-DUD in the English Dialect Dictionary.
Word Ways: Vol. 27
, Article 14.
Available at: http://digitalcommons.butler.edu/wordways/vol27/iss4/14