"Fold" is not archaic, but it may be more common in some regions compared to others (see "pop" vs. "soda"). The "-fold" suffix is in Webster's Ninth New Colleg

"Fold" is not archaic, but it may be more common in some regions compared to others (see "pop" vs. "soda"). The "-fold" suffix is in Webster's Ninth New Collegiate Dictionary and it does NOT have an "archaic" marking. It's also one of the answers when you ask Google to "define fold" (you have to look lower because suffixes are sorted after the main word). I use the suffix myself; it's nice and short when you need to express the concept.