alkaline

adjective

al·​ka·​line ˈal-kə-lən  -ˌlīn 

: of, relating to, containing, or having the properties of an alkali or alkali metal : basic

especially, of a solution : having a pH of more than 7

alkalinity

ˌal-kə-ˈli-nə-tē 

noun

Examples of alkaline in a Sentence

Recent Examples on the Web

The stain involves alkaline substances (like some pet urines), as vinegar can sometimes set these stains. —Daley Quinn, Southern Living, 3 Jan. 2026

SulfurSolve aims to avoid inefficiencies by using chemically stable carbonate ions to keep iron soluble and reactive at alkaline pH levels. —Sixteen Ramos, USA Today, 3 Nov. 2025

Lastly, alkaline water electrolysis (AWE) has been a reliable workhorse in the industry. —Kapil Kajal, Interesting Engineering, 17 Sep. 2025

The hardened sediment largely contained the mineral brucite — created through alkaline waste interacting with magnesium in the ocean water that resulted in the crust-like surface surrounding the barrels. —Maura Fox, San Diego Union-Tribune, 11 Sep. 2025

Word History

First Known Use

1682, in the meaning defined above

Phrases Containing alkaline

• alkaline battery
• alkaline earth metal
• alkaline hydrolysis
• alkaline phosphatase

Rhymes for alkaline

• acridine
• andesine
• anodyne
• anticline
• arginine
• asinine
• atropine
• benzidine
• borderline
• byzantine
• calamine
• caroline

Kids Definition

alkaline

adjective

al·​ka·​line ˈal-kə-lən  -ˌlīn 

: of, relating to, or having the characteristics of an alkali : basic

alkalinity

ˌal-kə-ˈlin-ət-ē 

noun

Medical Definition

alkaline

adjective

al·​ka·​line ˈal-kə-lən  -ˌlīn 

: of, relating to, containing, or having the properties of an alkali or alkali metal : basic

especially, of a solution : having a pH of more than 7

alkalinity

ˌal-kə-ˈlin-ət-ē 

noun

plural alkalinities