The following are SharePoint Dictionary Words of the Day Related to Hidden:
Hidden cell
A cell which no longer appears in a worksheet view because
it is contained within a hidden row or a hidden column.
Hidden column
A column that does not appear in a worksheet view because it
has its width set to zero. A column can be hidden if the outline is in a
collapsed selection.
Hidden row
A row which does not appear in a worksheet view because it
has its height set to zero. A row can be hidden if a user is filtering or if the
outline is in a collapsed selection.