You realize there is more than one "actual" definition, right?
Definition of logic
1a(1): a science that deals with the principles and criteria of validity of inference and demonstration : the science of the formal principles of reasoninga professor of logic
(2): a branch or variety of logicmodal logicBoolean logic
(3): a branch of semioticsespecially : SYNTACTICS
(4): the formal principles of a branch of knowledgethe logic of grammar
b(1): a particular mode of reasoning viewed as valid or faultyShe spent a long time explaining the situation, but he failed to see her logic.
(2): RELEVANCE, PROPRIETYcould not understand the logicof such an action
c: interrelation or sequence of facts or events when seen as inevitable or predictableBy the logic of events, anarchy leads to dictatorship.
d: the arrangement of circuit elements (as in a computer) needed for computationalso : the circuits themselves
2: something that forces a decision apart from or in opposition to reasonthe logic of war