turn on a sixpence

turn on a sixpence

1. Literally, of a vehicle, to turn or be able to turn very quickly. Primarily heard in UK. The steering is so good on this car that you can turn on a sixpence, even at high speeds.
2. By extension, to change focus, activity, opinion, or behavior very suddenly or abruptly. Primarily heard in UK. He's usually a nice guy, but his temper can turn on a sixpence sometimes. Politicians have no loyalty to their causes—they'll turn on a sixpence if it means they'll get more votes.
See also: on, sixpence, turn