(1) Having the properties of a [[base]].

(2) Containing sodium and/or potassium in excess of the amount needed to form [[feldspar]] with the available silica; e.g., an alkaline rock-in this sense sometimes written alkalic.

(3) Containing [[ion|ions]] of one or more alkali metals.

(4) Waters containing more than average amounts of carbonates of sodium, potassium, magnesium, or calcium.