|1.||open to the full extent|
|2.||(postpositive) exposed to attack; vulnerable|
|3.||uncertain as to outcome|
|4.||informal (US) (of a town or city) lax in the enforcement of certain laws, esp those relating to the sale and consumption of alcohol, gambling, the control of vice, etc|
Unresolved, unsettled, as in The fate of that former colony is still wide open. [Mid-1900s]
Unprotected or vulnerable, as in That remark about immigrants left him wide open to hostile criticism. This expression originated in boxing, where it signifies being off one's guard and open to an opponent's punches. It began to be used more broadly about 1940. Also see leave open.