My earlier suggestion had some important things in it, namely the "^" and "$". These say "match start of line", "match end of line". Without them any line with "armor" in it will match. I suggest copying the working one I did, and amending it slightly to replace "water" with "armor", like this:
So if you type 'water' it will cast water on a jug always. Typing 'water keg' or something like that will not do anything.
IF you want the option to have your water container vary so it's not always going to be a jug, then do this alias
BUT if you only have this alias above, typing 'water' will do nothing, you will always have to type 'water jug' or 'water keg' or whatever.
The best thing to do is create both the aliases above, so you can just type 'water' to cast water on your jug, but you can still type 'water <item>' to cast water on an item other than your jug.
Is that what you wanted?