Other forms: sojourned; sojourning; sojourns
A sojourn is a short stay or visit. If you want a fancy way to say that you took a trip to the countryside, you might talk about your country sojourn.
The verb is originally from the Latin prefix sub-, "under" plus diurnus, "of a day." You might refer to your vacation as a sojourn, but it might make more sense if you are describing a trip to Provence rather than a trip to Disney World. Or In figurative use, sojourn means "to delve" — your math teacher may stop midway through lessons on fractions for a brief sojourn into techniques for slicing pie.