Identically means “in exactly the same way,” or “to exactly the same degree.” Twins may dress identically. Two answers may be identically wrong — not just close, but the same mistake. Scientists say two samples are identically prepared when every step was the same. The word is stricter than similarly. Similarly leaves room for small differences; identically tries to close that room. In maths and science you will also hear phrases like “identically zero,” a careful way of saying “the same in every case, not just this once.” For everyday English, “exactly the same” will usually do; identically is the dressed-up version. Though actually, people stretch it: “identically dressed” in a magazine may only mean “so alike you cannot tell them apart,” not copy-for-copy. The tidy dictionary wants exact; real talk sometimes means “close enough.”