This is hard to tell, since the terms are older than any widespread use of the metronome. Anyway, they lack precision today (just compare metrome markings on the devices of different brands, or different web pages) and I can't imagine, that this was better in earlier times. For sure they only give a rough idea and are subject to interpretation and in that respect, I consider the meaning as quite stable over the centuries.
Your question already mentions the intensely discussed Allegro (and while cheerful suggests some speed, useful information ends here) but even worse in that respect is Affetuoso (with passion)