Personally, in the many branches of what are now conveniently refered to as 'ambigrams', we prefer the awkward-sounding 'symbiotogram'. This is the type where a word/phrase rotates into a different word/phrase. Other than its usage to highlight the concept of opposites, symbiotograms are also popularly used to combine two names - husband's-wife's being a good example - and as gifts for anniversaries, birthdays and/or as designs for a wedding invitation card.

.

What we love about symbiotograms is their ease in hiding a hidden meaning, especially when the hidden idea has a somewhat ironic or witty 'punchline' when juxtaposed with the first word/ phrase.

.

Some examples are our own 'world peace' rotating into 'a dead dream' and 'george w. bush' rotating into 'American jerk'.

.

For this post, inspired by NastyBasty's style, is the word 'nightmare' - a frightening dream - rotating into its opposite, the most blissful of dreams... (?)