riddle

a difficult problem

a coarse sieve (as for gravel)

pierce with many holes; "The bullets riddled his body"

set a difficult problem or riddle; "riddle me a riddle"

separate with a riddle, as grain from chaff

spread or diffuse through; "An atmosphere of distrust has permeated this administration"; "music penetrated the entire building"; "His campaign was riddled with accusations and personal attacks"

speak in riddles

explain a riddle