To sign one's initial(s), as an abbreviated signature.
Spatially first, placed at the beginning, in the first position; especially said of the first letter of a word.
Chronologically first, early; of or pertaining to the beginning, cause or origin.
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.
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.