[mass noun] A synthetic insecticide of the pyrethroid class, used chiefly against disease-carrying insects.
- ‘Pyrethrins and permethrin have a similar mode of activity.’
- ‘Put bug spray with permethrin on your boots and clothes.’
- ‘Common treatments for head lice include permethrin and lindane.’
- ‘Spray your clothing with permethrin insecticide spray.’
- ‘Experts consider permethrin the treatment of choice.’
1970s: from per- + (res)methrin, denoting a synthetic pyrethroid.
We take a look at several popular, though confusing, punctuation marks.