verb (used with object), un·stopped, un·stop·ping.
- to remove the stopper from: to unstop a bottle.
- to free from any obstruction; open: to unstop a sewer.
- to draw out the stops of (an organ).
verb -stops, -stopping or -stopped (tr)
- to remove the stop or stopper from
- to free from any stoppage or obstruction; open
- to draw out the stops on (an organ)