7) GAS: A fee for validating a transaction
Transaction fee has no name called, you are specifically talking about ethereum and ethereum tokens which gas is the fee used to send such tokens.
DeFi, CeFi, Gas and NFTs are all in the altcoins category.
This is what I was thinking too, afaik gas is terminology exclusive to the ethereum blockchain to mean transaction fees, it's not like we can use to me TX fees on any other blockchain.
I think both are acceptable depending on how it's used but blockchain sounds more appealing and acceptable!
Btw were does "block-chain" find itself in all this?