A minced oath, also known as a pseudo-profanity, is an expression based on a profanity which has been altered to reduce or remove the disagreeable or objectionable characteristics of the original expression; for example, "gosh" used instead of "God", "darn" or "dang" instead of "damn", "heck" instead of "hell", and "blimey" instead of "May God blind me!" Nearly all profanities have minced variants; the words that are most taboo give rise to the most.
~from the wiki [link]
Dang, Bob! And blimey heck too!