adjective
- having part or all of the caffeine extracted: decaffeinated tea.
verb (used with object), de·caf·fein·at·ed, de·caf·fein·at·ing.
- to extract caffeine from: to decaffeinate coffee.
verb
- (tr) to remove all or part of the caffeine from (coffee, tea, etc)
1909 (implied in decaffeinated), from de- + caffeine + -ate (2).