What is "heterogram"

n. A word of phrase in which no letter occurs more than once

A heterogram (from hetero-, meaning "different", + -gram, meaning "written") is a word, phrase, or sentence in which no letter of the alphabet occurs more than once.

An isogram, in which all letters occur an equal number of times, is the same as a heterogram when each letter occurs once.

A heterogram may be distinguished from a pangram (a holoalphabetic sentence), which uses all of the letters of the alphabet (possibly more than once). A perfect heterogram is, however, the same as a perfect pangram, since both consist of all letters of the alphabet with each represented exactly once.

Abjads and abugidas, in which only the consonants are represented in the basic graphemes, have a naturally high incidence of heterograms.

Heterogram may refer to:

• Heterogram (literature), a word, phrase, or sentence in which no letter of the alphabet occurs more than once
• Heterogram (linguistics), the use of a graph from a foreign language in a text as a logogram

Heterogram (from [Greek] heteros, meaning "different", + -gram, meaning "written") is a term used mostly in the study of ancient texts ( philology), referring to a special kind of a logogram consisting of the written representation of a word in a foreign language. In most cases, the two languages share the same script. However, while the word in the foreign language may be written either phonetically (representing the sounds of the foreign language) or logographically, in the borrowing language it is necessarily a logograph, since there is no relationship between the symbols used and the pronunciation of the word in the borrowing language.

Heterograms are frequent in cuneiform scripts, such as the writing of Akkadian, which uses Sumerian heterograms. In Middle Iranian scripts derived from the Aramaic scripts (such as the Pahlavi scripts), all logograms are heterograms coming from Aramaic. Sometimes such heterograms are referred to by terms identifying the source language such as "Sumerograms" or "Aramaeograms".