What does the Google Translate shield icon mean? How can a word be protected?
It is not "protection" but validation. Google Translate allows users to participate in kind off validation program which is able to improve the complexity of translation AI algorithm. This translation AI algorithm kicks in whenever you try to translate phrase or sentence and its purpose is to improve translation experience and make it more "smart-like" because ordinary "word-for-word" (robotic) dictionary translation is already on its edge eg. out-dated. In other words, the validation icon (should) signalise that translation (between two completely different languages which have no common ground nor logic, history etc.) is solid.