意外
いがい · igai · JLPT N3 · na-adj
unexpected
🎁 意外 = intention + outside: something that falls outside what you expected
意 means mind, intention or expectation, and 外 means outside. Something 意外 lands outside your expectations, so it is unexpected or surprising. It also sounds a bit like 'ee, guy!', which is what you might say when something catches you off guard.
外 — evening 夕 + divination 卜
Originally a compound of 夕 (evening) and 卜 (divination). Ancient Chinese divinations were performed in the morning; doing them at evening (夕) was considered irregular or 'outside' the norm. From this sense of deviation, 外 came to mean 'outside' or 'external'.