The game term would be "take an attack action".
Rubbish! You don't need to take the Attack action in order to make an 'attack' (game term). Opportunity attacks, attack rolls from the Cast A Spell action when casting
booming blade/green-flame blade, and so on. The Attack action has nothing to do with the game's definition of what an 'attack' is.
There's no reason to believe that the real world meaning of the word would not apply since there is no place where the words state that "as far as the game is concerned this is what we mean when we use the term attack". Yes, there are rules on how to resolve certain types of attacks, that does not mean that anything not covered by that section of the book would not be considered an attack.
Yes there is: PHB p192 in the section Making An Attack tells us what an 'attack'
is as a game term. BTW, it has no burden to list all the things that are
not an 'attack'; all it needs to do is list the things that
are an 'attack', and therefore anything not on that list has failed to meet the criteria for an 'attack' as far as the game rules are concerned.
"If there's ever any question whether something you're doing counts as an attack,
the RULE is simple: if you're making an attack roll, you're making an attack."
The rules are permissive. They are what they say they are. You cannot point to things it does not say and pretend like they meant this too. You cannot say that
mage armour ends if the target throws sand in someone's eyes on the grounds that there is nothing in the spell description that says the spell
doesn't end if I throw sand! I can't claim that my 1st level fighter can cast 2 7th level wizard spells per short rest on the grounds that nowhere in the description of the fighter class does it say that 1st level fighters cannot cast 7th level spells!
And yet, here you are saying, "I know that the game defines 'attack' as something that involves an attack roll, but it
doesn't say that things that
don't have an attack roll are
not attacks, so they are!" It's the same absurdity!
It goes back to fundamentals. Unless the rules say otherwise, use common terminology. The rules clarify how to resolve certain types of attacks, it does not redefine the term, it does not need to.
When the game uses a term which is a game term in the context of how one game mechanic interacts with another, they do indeed mean it as a game term and not as common language!
You get +2 AC for a shield! Great, +2 AC just from using this brand of insect repellent! What? Surely they are using 'shield' as natural language and not the thing they have
already defined as a shield in the equipment chapter?
That and I think it's silly that dropping a nuke /using a flamethrower/breathing fire on someone would not be considered an attack.
No, what is silly is that 'attacking' pops invisibility! The two have no cause/effect relationship!
'Normal' people, those who have no experience of RPGs, would not connect the two. They don't understand 'attack' as a game term, but they also would not assume that hitting someone makes your magic spell stop working!
The fact that an 'attack'
does pop invisibility is a pure game mechanic with no origin in reality OR legend. It is a game mechanic, it refers to other game mechanics to define what happens when the two game mechanics interact.