The two dots in "naïve"

• Mark missing from "naive"
• A diacritical mark (two dots) placed over a vowel in German to indicate a change in sound
• Umlaut doppelganger
• "The two dots in "na"
• The two dots in "naГЇve"

Wiktionary Word definitions in Wiktionary
n. (alternative form of diaeresis English)

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Diaeresis \Di*[ae]r"e*sis\, Dieresis \Di*er"e*sis\ (?; 277), n.; pl. Di[ae]reses or Diereses . [L. diaeresis, Gr. ?, fr. ? to divide; dia` through, asunder + ? to take. See Heresy .] (Gram.) The separation or resolution of one syllable into two; -- the ...

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
also diaeresis , 1610s, "sign marking the division of a diphthong into two simple sounds," from Late Latin diaeresis , from Greek diairesis "division," noun of action from diairein "to divide, separate," from dia- "apart" (see dia- ) + hairein "to take" ...