The act of departing suddenly or the place where someone has decamped from.
From decamp + -ment (suffix forming nouns of action or state). Follows English patterns for converting verbs to nouns.
The 'decampment' of wealthy residents from New York to Miami during the pandemic showed how this old military word applies to modern migration patterns driven by taxes and lifestyle.
Complete word intelligence in one call. Free tier — 50 lookups/day.