Unhyphenation

Unhyphenation is the process of removing hyphenation marks and rejoining word fragments that have been split at line ends. It is used in typesetting, document conversion, and text processing to restore the original form of a text or to produce clean plain-text output. The goal is to produce continuous words suitable for reading, indexing, and search without artificial line-end hyphens.

Practically, unhyphenation identifies a hyphen at the end of a line and concatenates the preceding and following fragments. However, not every hyphen indicates a line break; some denote legitimate hyphenated compounds. Algorithms often rely on dictionaries, language models, or morphological rules to decide when to join, and may require exceptions for prefixes, suffixes, or proper nouns. In some workflows, the hyphen and line break are removed entirely; in others, only the hyphen is removed and a space or no space is inserted based on context.

Applications include preparing text for search indexing, improving consistency in corpora, and digitizing documents where line-ending hyphens were introduced by the formatter rather than by the word structure.

Challenges include ambiguity in whether a hyphen is legitimate, language-specific hyphenation conventions, and preserving capitalization and punctuation. Unhyphenation is a common step in text normalization and is closely related to hyphenation techniques and soft-hyphen handling in Unicode.