Merriam-Webster Collegiate Dictionary - initial

 I. adjective  Etymology: Anglo-French & Latin; Anglo-French iniciel, from Latin ~is, from initium beginning, from inire to go into, from in- + ire to go — more at issue  Date: 1526  1. of or relating to the beginning ; incipient his ~ reaction  2. placed at the beginning ; first the ~ word of the verse  • ~ly adverb  • ~ness noun  II. noun  Date: 1627  1.  a. the first letter of a name  b. plural the first letter of each word in a full name found that their ~s were identical  2. a large letter beginning a text or a division or paragraph  3. anlage, precursor; specifically a meristematic cell  III. transitive verb  (~ed or ~led; ~ing or ~ling)  Date: circa 1864  1. to affix an ~ to  2. to authenticate or give preliminary approval to by affixing the ~s of an authorizing representative