In this case, I mean this definition of “key”:
A systematic explanation of abbreviations, symbols, etc., used in a dictionary, map, etc.
Having a toddler means that you likely have a few words or phrases that have meaning around your own home, but would completely confound strangers. Here are a few of ours:
Pop bottles = Children who are acting silly
Monkeypuppy = Meerkat
String theory music = classical music
Planets noodles = Israeli couscous
Have any of your own house language to share, either from your kids or from your own childhood?