initial
adjectiveOf, relating to, or occurring at the beginning; first.
adjectiveDesignating the first letter or letters of a word.
nounThe first letter of a proper name.
nounThe first letter of each word of a person’s full name considered as a unit.
nounThe first letter of a word.
nounA large, often highly decorated letter set at the beginning of a chapter, verse, or paragraph.
transitive verbTo mark or sign with initials, especially for purposes of authorization or approval.
To put one’s initial or initials to or on; sign or mark with initials: as, an initialed handkerchief; initialed paper.
nounIn steam-engines, an abbreviation of