How do you spell Initialed

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