The current acid-base tag only defines acidity/basicity in Bronsted/Lowry terms. I propose the creation of a Lewis-acidity/basicity tag.
An acid is either a proton donor, or an electron-pair acceptor. A base is either a proton acceptor, or an electron-pair donor. In aqueous solution, acids have a pH less than 7 and bases have a pH greater than 7.
Also, what's up with the arbitrary reference to the pH of 7? Let's not perpetuate the misconception that any neutral solution has a pH of 7. That's only for neutral solutions at a temperature of 25 degrees Celsius. The only condition for solution neutrality is A(hydronium ion) = A(hydroxide ion) or more simply, [hydronium ion] = [hydroxide ion].