open investigation

: having no enclosing or confining barrier : accessible on all or nearly all sides

: being in a position or adjustment to permit passage : not shut or locked

: having a barrier (such as a door) so adjusted as to allow passage

: to move (something, such as a door) from a closed position

: to make available for entry or passage by turning back (something, such as a barrier) or removing (something, such as a cover or an obstruction)

: to make available for or active in a regular function

: opening

: open and unobstructed space: such as

: open air

: to observe or study by close examination and systematic inquiry

: to make a systematic examination