Noun
A diacritic consisting of two dots ( ¨ ) placed over a letter, used among other things to indicate umlaut or diaeresis.
Synonym: diaeresis
(Can we verify this sense?) "an initial phase in the psychotic process that is characterized by intense anguish, an experience of hostility and a feeling of imminent catastrophe".
Source: en.wiktionary.orgDaneel also comes into conflict with a robot known as R. Lodovic Trema whose positronic brain was infected by a rogue AI — specifically, a simulation of the long-dead Voltaire — which consequently frees Trema from the Three Laws. Source: Internet