Phishing, in a gambling context
Phishing is the use of a fake message to trick you into handing over credentials or money. In gambling it has a specific shape, because the attacker knows two things about you that make the bait land: that you hold a balance somewhere, and that withdrawals and verification are already sources of anxiety. So the message imitates exactly the communications you half-expect — a security alert, a verification request, a withdrawal confirmation — and uses that expectation against you.
The crucial distinction from the other scams on this site is what is being attacked. A cloned site waits for you to arrive and deposit; a withdrawal trap obstructs money you have already paid in. Phishing reaches out to you, at a real account you actually hold, and steals the key to it. It does not need the casino to be a scam at all — the target is your access to a legitimate account, which is why phishing affects players at fully licensed, reputable operators just as much as anywhere else.