[n] a flat plate that controls or directs the flow of fluid or energy
[v] be a mystery or bewildering to; "This beats me!"; "Got me--I don't know the answer!"; "a vexing problem"
[v] check the emission of (sound)
[v] hinder or prevent (the efforts, plans, or desires) of; "What ultimately frustrated every challenger was Ruth's amazing September surge"; "foil your opponent"
amaze, baffle board, beat, bewilder, bilk, cross, dumbfound, flummox, foil, frustrate, get, gravel, mystify, nonplus, perplex, pose, puzzle, queer, regulate, scotch, spoil, stupefy, thwart, vex