Crossword puzzle clue "word with level or form"

Word with level or form

Low-level pollution or high-level protection

Warning sign at a train station's food court? (NOTE: The original sign, without my additions, actually exists. It's in Grand Central Terminal in NYC, on the lower level — the food court level. The sig

Class, level or class level

Management level or theater level

Word form with form

Level: Comb. form

Jumble wordplay applied to every Across answer except this one, yielding another word/word form