Meaning of INITIAL in English

adj. 1 original, primary, first; prime, beginning, incipient, inaugural, opening, introductory, commencing His initial plan, to take the children, was vetoed by his wife It is best to tread cautiously during the initial stages of the programme.

v. 2 sign, approve, endorse Please initial the clauses of the contract that we have changed

n. 3 monogram The initial 'M' is on all their towels

Oxford thesaurus English vocab.      Английский словарь Оксфорд тезаурус.