Magus_Jerel said:
Reiterate:
attack: Any of numerous actions intended to harm, disable, or neutralize an opponent. The result of an attack is determined by an attack roll.
Your "specific sense" interpretation takes a literal reading of the second sentence.
Now - lets play this two ways...
1. Any of numerous actions intended to harm, disable, or neutralize an opponent.
CDG is most definitely an action intent on
"harming and neutralizing" an opponent... so it IS an attack action
or...
It's an "attack" in the general sense, but it is not a "melee attack action" as defined by the PHB on page 122.
Check the PHB, page 133. It explains the difference between doing a regular melee attack and a CDG on a helpless opponent.
2. The result of an attack is determined by an attack roll.
hmm... magic missile, fireball, cone of cold, and meteor swarm don't require an attack roll... so they aren't attacks - right?
Exactly. Casting a spell is a magic action, not an attack action. (See the PHB, page 125)
Lets take one level of cleric - and use sanctuary... then focus on wizardry.
Casting fireball isn't an attack as it doesn't require an attack roll... or does it?

kewl - means I can hide behind my sanctuary spell and just blast away all day long...
It's an attack in the general sense, but it's not an attack action. There is a difference there that you seem to be missing.
Sanctuary protects against attacks in the general sense. Sanctuary would protect against a CDG, an attack spell, or a normal melee attack, even though only one of them are attack actions.
Caliban - you get caught dancing between "general" and "specific" definitions dependent upon the point you want to espouse. One phrase - ONE definition;
Wrong. Two meanings are recognized in the rules. A CDG is a type of attack (in the general sense), but it is not a melee (or ranged) attack action. It's a Standard Action (when using Death Blow).
More to the point, since it's a standard or full round action, you can't do it in place of the extra attack granted by Expert Tactician (which is what the question was really about). The chart on page 128 of the PHB lists the attacks that can substitute for a single melee attack. CDG is not one of them.
You can try to play all the word games you like, but it really won't change the rules, no matter how hard you try.
or are you wanting to play "Accident Dicto Simpler"?
Since I actually know what I'm talking about, I have no fear of your silly latin phrases.