the state of being urgent; an earnest and insistent necessity
"The sudden urgency in his voice made it clear that we needed to leave immediately."
an urgent situation calling for prompt action
"I'll be there, barring any urgencies"
"they departed hurriedly because of some great urgency in their affairs"
insistent solicitation and entreaty
"his importunity left me no alternative but to agree"
The quality or condition of being urgent
"The urgency in her voice made everyone realize how critical the situation had become."
In plain English: Urgency is how badly something needs to be done right now because there isn't much time left.
"The urgency in his voice made everyone realize they needed to leave immediately."
Usage: Avoid using "urgency" to describe an event itself; instead, use the adjective "urgent." This noun specifically refers to the degree of immediacy required rather than the situation creating that need.
The word urgency comes from combining English urgent with the suffix -ency to form a noun meaning state of being pressing. It entered modern usage as a direct extension of the adjective's sense of requiring immediate attention.