Definition & Meaning of "fair dinkum"in English

What does "fair dinkum" mean in Australian slang?

The structure combines "fair" (just or reasonable) with "dinkum" (a word of uncertain origin, possibly from English dialect "dingham" meaning work or a fair share, or from Cantonese "ding kam" meaning top gold). It is used in Australian English to mean genuine, honest, or true, often as an adjective or exclamation to confirm authenticity. People typically say "He's a fair dinkum bloke" or "Fair dinkum, I didn't see that coming."