Address poisoning is the common short name for the wallet address poisoning scam, and that entry describes the scheme in detail. The term refers to the act of "poisoning" a victim's transaction history with fake entries.
The attacker watches a public blockchain for active wallets, then generates a wallet address whose first and last characters match an address the victim often pays. It sends a tiny or zero-value transfer, or a fake token, from that look-alike address so that it appears in the victim's recent activity. If the victim later copies an address from their history rather than from a trusted source, they may send funds to the attacker. Because on-chain transactions are generally irreversible, the money is usually lost.
Address poisoning is used mostly as a verb-like description of the technique, while the full entry name stresses that it is a scam. Defences include checking the whole address, using saved address books, sending a small test amount first and using wallets that flag suspicious look-alikes. It is one of several crypto fraud prevention concerns alongside phishing.