Novation
Agreement of parties to a contract to substitute a new contract for the old one.
Nugatory
Of no force or effect; invalid.
Nuisance
The unreasonable, unwarranted and/or unlawful use of property, which causes
inconvenience or damage to others, either to individuals and/or to the general
public.
Nullity
Something which may be treated as nothing.
Nunc Pro Tunc
Latin, deemed retroactive.