Transitory.
(adj.) 1. Having the quality of passing away; not lasting; fleeting, momentary, brief; transient.
2. a. Having a passage-way, allowing passage through. Obs. rare.
b. Of the nature of a passage or transition; transitional. rare.
(n.) 1. A transitory or fleeting thing. (Chiefly in pl.) Obs.
2. a. The transverse limb of the cross-staff
b. A transit-instrument. Obs.
Source: http://www.oed.com/view/Entry/204830?redirectedFrom=transitory#eid
Transitory Event Building.
A space which is primarily portrayed by the characteristics of flexible, mobile and adaptable design.
