illegibilis

Illegibilis is a term of Latin origin used in palaeography, codicology, and related disciplines to describe text, inscriptions, or scripts that are difficult or impossible to read. The adjective illegibilis derives from Latin illegibilis (not readable) and is used to characterize a source rather than to identify a specific script type. In English-language scholarship the term is occasionally encountered in Latin phrases or in discussions of manuscript difficulty.

Causes of illegibilis include physical deterioration of materials (fading ink, parchment damage), chemical degradation, harmful environmental conditions, as well as legibility issues arising from script forms, abbreviations, ligatures, or dense marginalia.

Implications: illegibilis passages complicate transcription, dating, authorship attribution, and text-critical work. Researchers document the illegibilis portions, annotate uncertain readings, and employ imaging techniques to recover text.

Modern techniques: multispectral imaging, infrared photography, UV illumination, and digital enhancement have increased recoveries from illegibilis sections. OCR and handwriting recognition face limitations on such sources, making human scholarship essential.

See also: illegibility, legibility, palaeography, codicology, manuscript studies.