diaeresis or dieresis /dī-ērˈi-sis or -erˈ/

1. A mark ( ¨ ) placed over a vowel, esp the second of two adjacent ones to show that it is to be pronounced separately, as in naïf
2. A pause or break where the end of the word coincides with the end of a foot (prosody)

• preference stock
• preferential
• preferential duty
• preferentialism
• preferentialist
• preferentialists
• preferentially
• preferential shares
• preferential stock
• preferential tariff
• preferment
• preferments
• preferrable
• preferred
• preferred ordinary shares
• preferred shares
• preferrer
• preferrers
• preferring
• prefers
• prefigurate
• prefigurated
• prefigurates
• prefigurating
• prefiguration