I had a giggle like everyone the first time I heard it. Mansplain. The perfect epithet for the boardroom bullies, the down-talking politicians, the Twits and shock jocks who embody the 16 per cent gender pay-gap, the underrepresentation of women in just about everything important. The unfairness that we're still beating our heads against the glass ceiling so many decades after The Female Eunuch.

Like thousands of women, I threw it around like the glorious little explosion of wit that it is. And most of my male friends laughed along, if a little uncomfortably.

But then I started getting this sinking feeling, the kind you got when your nine-year-old self (the one with short hair and a Sarah Connor figurine) won an argument with your brother about who got to sit in the front seat of the car, but you did it by kicking him in the shins and yelling "shotgun!" while he howled in pain. Somehow, the rosy glow of that hallowed front seat was tarnished by the knowledge that you went real low to get there.

When I called someone a mansplainer, I'd hit below the belt.