Definition of initial

• a. - Of or pertaining to the beginning; marking the commencement; incipient; commencing; as, the initial symptoms of a disease.
• a. - Placed at the beginning; standing at the head, as of a list or series; as, the initial letters of a name.
• n. - The first letter of a word or a name.
• v. t. - To put an initial to; to mark with an initial of initials.