The act of preventing or hindering; obstruction of action, access, or approach; thwarting.

Preventing, hindering, or acting as an obstacle to. / Carried out to deter military aggression. / Slowing the development of an illness; prophylactic. / (obsolete) Going before; preceding.

(dated) A thing that prevents, hinders, or acts as an obstacle to. / (nonstandard) A thing that slows the development of an illness. / A contraceptive, especially a condom.

Third-person singular simple present indicative form of prevent

plural of preventive

Tending to prevent; preventative.

plural of prevention

The quality of being preventive.

(oil industry) A device that sits at the surface interface of an oil well and prevents a blowout from occurring by closing the orifice, allowing material to flow from the oil reservoir out through the shaft.

Maintenance done to keep something in working order rather than to repair damage that has already happened.