What does "forced meaning" mean?

Since this book is intended primarily for students in the early stages of their Latin studies, all the forms have been omitted which they are not likely to meet in their readings because of their forced meanings.
What does “forced meaning” mean?

Hi David,

If you translate words from one language to another, you find different connotations if you look at the individual words. And because you don’t want to distract learners with asymmetrical differences in word meaning (most concepts usually have an equivalent in each language) in the beginning, you try to avoid connotations of words with a more unusual meaning. Same applies to words which take on a meaning because they make sense in context when used in a certain way. Those words have a ‘forced meaning’.

In art, seemingly meaningless photos are attached with a forced meaning. Have a look at this image