Hi Mara. Yes, the word 'jaunt' is a more "colorful" but less commonly used synonym of 'trip.' That's to say, we're feeling pretty perky when we use it. It's said in fun: Let's take a jaunt up the coast! Let's take a quick jaunt on your new motorcycle! Let's jaunt up ahead and surprise them!
Yes, Mara, usage of the word jaunt is strictly reserved for people with a tendency toward smiling quite often, people inclined to a little mischief-making now and then, those who like to hug and kiss a lot, eccentric characters who are bold enough to find hilarity in our human predicament, those rascals who truly find enjoyment in cobbling funny words together.
To me a jaunt is more aimless than a trip - "a jaunt down to Wigan" sounds all wrong, Brioche, as most jaunts would be unlikely to have a target. One is more likely to leave home with no particular destination in mind.
Around here, a jaunt is quite specifically a supposed business trip that has a distinctly social content. A weekend in Dublin for a one-hour product demonstration on a Saturday morning on the day of the Ireland-Wales rugby international. That is a jaunt, a jolly, or a legitimate business expense.