What is the difference between "jaunt" and "excursion", "trip" and "outing"? Can we say "secretive outing" or "secretive absence"?

I found the following sentence in today's New York Times. Apparently, secretive jaunt of New York Mayor Michael R. Bloomberg sounds to carry some speculations. And for a foreign English learner like me, jaunt seems to be a 'less well-worn' word (Is this expression right?). What is the difference of meaning among jaunt, excursion, outing, trip, and journey?

Mayoral Sign-Out Sheet? Secretive Jaunts Spur a Thought: Angered by Mayor Michael R. Bloomberg's refusal to say where he was during the December blizzard, lawmakers may consider requiring mayors to acknowledge absences.

Solution 1:

A jaunt is

A short trip or excursion, usually for pleasure; an outing.

The meaning is that Bloomberg was off having fun somewhere while the city endured a miserable blizzard.

Oh, and among the rest of the synonyms:

• trip is the common term that defines some kind of "going out"
• excursion is simply a trip of some kind
• outing is a trip that is (usually) taken for pleasure
• journey is a long trip of some kind; it's defined as any kind of trip, but the implication is that it may be arduous and often discoveries are made along the way

Solution 2:

There's another solecism in that Times article, Yoichi, which is misuse of the word "secretive." It applies essentially to people and not to inanimate objects: the mayor himself may be secretive, for example, but the trips he takes out of town are secret.

[There's another word that you might like for another kind of trip that a politician takes: junket.]