Where a going is aimed. A destination gives a journey its shape without being most of it.
Latin destinatio (a fixing, appointment), from destinare (to make firm, determine), from de- (thoroughly) + stare (to stand); where a going is aimed, fixed in advance of the journey that will reach it.
Latin stare is to stand, and a destination was first something made to stand firm, fixed before the journey begins, so the journey has something to aim at rather than merely wander. Fixing the end this way is what turns motion into a route.