Imagine a language with a register for certain religious holy days. On these days, lots of distinctions are conflated: 'dog', 'lamb' and 'cow' generalize to cover all four-legged furry animals; lizard generalizes to cover four-legged and fewer-legged small animals (including also small mammals - which are included under dog/lamb/cow as well). All tools for woodwork are 'hammers' or 'saws' - depending whether they can be used to merge or split things.
The majority of words that are not "prototypical" for a wider class are left out of use on these days.
This also happens with verbs; however, multiple different conflations may overlap partially, and sometimes, two verbs are used together to 'cheat' the taboo - i.e. "walk stand" for walk, since "walk" now includes dancing, crawling, trodding, trampling, moving about by cart, riding horses, etc; "stand" includes standing, sitting, lying, etc. Likewise, nouns sometimes are combined - dog lizard for mouse, for instance.
This idea was posted out of order with regards to idea 156 because it occurred significantly later (I had already written most of idea 156, but this took way less time to write).
Finally, adverbs too are made less specific - tomorrow now signifies any future time and is the only word used for that, yesterday likewise in relation to the past.