Air-tight and Beyond doubt

Air-tight adjective - Not allowing air or gas to pass in or out.

Beyond doubt and air-tight are semantically related. In some cases you can use "Beyond doubt" instead an adjective phrase "Air-tight".

Beyond doubt adjective - Too obvious to be doubted.

Air-tight and beyond doubt are semantically related. Sometimes you can replace phrase "Air-tight" with "Beyond doubt", this phrases are similar.