Acidify/əˈsɪdɪfaɪ/ Definition 1 of 2Pro Tip 1/3Technical Context Used in scientific or precise discussions about chemical properties. Farmers often acidify soil to influence crop growth. Pro Tip 2/3Process Description Describes the action of making something acidic, over time. Leaving milk out will eventually acidify it. Pro Tip 3/3Not Always Deliberate Can happen naturally or unintentionally, not just by human action. After the rain, the lake water started to acidify.