N.A.
Net Absolutely; no deductions from gross premium for brokerage or discount.  

N.D.
Non-Delivery.  

N.R.A.D.
No Risk After Discharge or No Risk After Landing (N.R.L.D.) especially in use for merchandise consigned to an area where political or other conditions are unsettled.  

N.R.A.S.
No Risk After Shipment.  

N.R.T.O.R.
No Risk to Attach till on Rail.  

N.R.T.W.B.
No Risk to Attach till Water Borne; particularly used where congestion (conflagration hazard) exists.  

Named Perils Policy
Any marine policy limiting cover to perils specifically listed in the policy; opposed to All Risks policy. All Risk

Narrow Body Aircraft
Aircraft with one corridor, such as a DC-9 and a Boeing 737.  

Navigation
Act of determining position, location and course to the destination of an aircraft or a vessel.  

Negligence
Imprudent action or omission which may cause injury, damage or loss.