Ubiquitous definition: existing or being everywhere , especially at the same time; omnipresent.. See examples of UBIQUITOUS used in a sentence. When something seems like it's present in all places at the same time , reach for the adjective ubiquitous. The meaning of UBIQUITOUS is existing or being everywhere at the same time : constantly encountered : widespread. How to use ubiquitous in a sentence. Did you know? The word ubiquitous finds its roots in the Latin term ubique, meaning “everywhere.” It entered the English language in the early 19th century, derived from ubiquity, which referred to the ...