非常
fēicháng · HSK 1
very
非 = not + 常 = ordinary → not ordinary = extraordinary
非 means 'not/non-' (as in 非法 illegal) and 常 means 'ordinary/constant'. Together 非常 literally reads 'not ordinary', which extends to the adverbial sense 'very, extremely' in modern usage.
非 — two opposing wings 羽-like form
Originally a pictograph showing two wings spread in opposite directions, symbolizing things facing away from each other. From this 'opposition' image came the meaning 'not' or 'wrong.' It is also used as a phonetic component in many characters like 排, 悲, and 罪.
常 — 巾 (cloth) + 尚 (phonetic, 'esteem')
Originally written 裳, 常 was a phono-semantic compound: 巾 ('cloth') gave the meaning and 尚 supplied the sound, referring to a long lower garment or skirt. Over time the meaning shifted from 'everyday garment' to 'ordinary, regular, constant', while 裳 took over the original clothing sense.