The term 'annum' is a Latin word meaning 'year'. It is often used in legal and financial contexts to refer to a period of one year. The crossword solutions for the term annum are 'year' (4 letters) and 'PER' (3 letters). 'PER' is a Latin preposition meaning 'THROUGH' or 'for each', and it is often used to indicate a period of time. Therefore, the combination of 'year' and 'PER' can be used to refer to a period of one year.