Antonyms for the phrase "opening wide" could include "closing tightly," "narrowing," "shutting," "blocking," and "constricting." These words suggest the opposite of opening something fully, or expanding its space. For example, if you open your mouth wide, the opposite would be to close it tightly or shut it altogether. Similarly, if you open a doorway or window wide, the opposite would be to narrow or close it completely. These antonyms help to emphasize the contrast between opening and closing or limiting, indicating the limitations that can occur when something is not open and expansive.