Definition - What does Partial Defense mean?
A partial defense is a type of legal defense in which a defendant does not completely deny the charges or accusations against them, but instead only claims to be liable for part of them, or for a reduced amount of damages.
A trial will still have to take place to determine whether or not the defendant will be held liable for the parts of the accusation that they claim no responsibility for.
Justipedia explains Partial Defense
There are many circumstances that could yield a partial defense. For example, if a person is accused of owing $100,000 in damages by a plaintiff, but they believe that they are responsible for only $50,000, then they may try to make a partial defense. In such a situation, the defendant would agree to pay $50,000 but try to prove through a trial that they are not liable for the remaining amount.