B2(held or kept together) firmly or closely: I can't untie the knot - it's too tight.This lid is on very tight.The people stood talking in tight groups.Hold on tight when we go round this corner.Check that windows and doors are shut tight (= completely closed) before you leave.The plastic cover was stretched tight (= stretched as much as it could be) across the tank.→ See alsoairtight, watertightTight and tightening