- preventative
- preventive, preventativeBoth words are in use as adjectives meaning ‘serving to prevent’, especially in medicine, and also as nouns denoting a substance or procedure that does this. Preventive is the commoner by a long way (with four times as many occurrences in the OEC), understandably in view of its more comfortable form:
• Preventive medicine may be more effective if problem-based learning programmes are established in place of the traditional methods of education —Physiotherapy, 1990
• The most powerful preventives are on the shelves of your natural foods store —Better Nutrition, AmE 2003 [OEC].
When preventative occurs it is more usually in generalized contexts qualifying words such as action and measure rather than (for example) medicine:• When we hear talk of a ‘preventative strike’ we must translate that term into what it really means: a surprise attack —V. Mollenkott, AmE 1987.
Modern English usage. 2014.