Some words have good meanings in normal conversation, and different meanings in science. 'Theory' is one such. But one that is seriously hazardous to try to interpret until you know the full context is 'rapid'. For folks studying chemical reactions, that can be a femtosecond. For geologists studying tectonic processes, it can be millions of years ('rapid uplift of the Himalayan plateau').
Even within a field, say glaciology, you can be looking at a few hours (rapid breakup of an ice shelf) to a few thousand years (rapid onset of an ice age).
Other contributions of words that vary widely between fields and even within fields? We'll take 'sudden' and the like as covered by 'rapid'.
Brian Schmidt has a video
9 hours ago