"visible to the naked eye," 1841, from macro- + ending from microscopic. Related: Macroscopical; macroscopically.
word-forming element meaning "long, abnormally large, on a large scale," taken into English via French and Medieval Latin from Greek makros "long, large," from PIE root *mak- "long, thin."
1732, "pertaining to or functioning as a microscope;" see microscope + -ic. Meaning "of minute size" is from 1742. Related: Microscopical (1660s as "pertaining to a microscope"); microscopically.