Initial meaning : The first letter of a word or a name. In plural, the first letter of each word of a person's full name considered as a unit. A distinguished initial letter of a chapter or section of a document. Onset, part of a syllable that precedes the syllable nucleus in phonetics and phonology. To sign one's initial(s), as an abbreviated signature. Chronologically first, early; of or pertaining to the beginning, cause or origin. Spatially first, placed at the beginning, in the first position; especially said of the first letter of a word.