Crossword solverSynonyms for thermionic tube10 crossword answers for “thermionic tube” (10,4), sorted by letter count.How many letters?All10517181921211411511611815 letters 1diode7 letters 1pentode8 letters 1klystron9 letters 2acorn tube(5,4)magnetron12 letters 1electron tube(8,4)14 letters 1rectifying tube(10,4)15 letters 1rectifying valve(10,5)16 letters 1gas-discharge tube(3-9,4)18 letters 1electron multiplier(8,10)