Crossword clues for the word: GCA The word GCA has appeared as an answer to at least 4 crossword clues on different crossword puzzles. Crossword clues for GCA Showing 1 to 4 of 4 results Clue(s) "1968 federal law regulating firearms, for short" Air-traffic abbr. Landing with tower assistance: Abbr. Tower-aided landing: Abbr.