I know what you mean, but for the sake of precision, no, the words “deuterocanonical” and “apocryphal” are not “synonymous” (i.e.have the same meaning). As you say, they do refer to the same sets of books, but we say “deuterocanonical” because they are the “second-canon” or “also-canonical”. Protestants call them “apocrypha”, meaning hidden or secret because they doubt their authenticity as Scripture.
As Catholics, books WE call “apocrypha” include books like 3 and 4 Maccabees and Psalm 151…which the Greek Orthodox recognize to be canon. Orthodox call these and our deuterocanonical books by a different term, since “deuterocanonical” has an entirely different meaning to them.
