Haplography is the act of writing once what should be written twice. For example, the English word idolatry, the worship of idols, comes from the Greek

Greek language

Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 eidololatreia, but one syllable has been lost through haplography. Other examples are "endontics" for endodontics, and "voraphilia" for "vorarephilia".

There are various instances of conventionalized haplography in English. For example, the normal punctuation mark for a declarative sentence in English is a period

Full stop

A full stop is the punctuation mark commonly placed at the end of sentences. In American English, the term used for this punctuation is period. In the 21st century, it is often also called a dot by young people...

. However, if a declarative sentence ends with a word that is abbreviated with a period (etc., Ltd., or Inc.), the sentence-final punctuation mark is omitted. This is clear by comparison with other sentence types, such as interrogative or exclamatory sentences, where the punctuation is not reduced at the end.

• Philip K. Dick wrote the novel Lies, Inc. And then...
• Who wrote the novel Lies, Inc.?
• So, it was Philip K. Dick who wrote the novel Lies, Inc.!