OKAY HOLD UP I KNOW THIS IS A SHITPOST BUT I HAVE A DEGREE IN THIS
Okay, so when we talk about the meaning of words, we are talking about denotation, the dictionary definition of the word, and connotation, the context in which native speakers associate with the word. Connotation is why just looking up synonyms of words doesn't always work.
When teaching this to ESL learners, my favorite example is the word "accumulate." Accumulate means to gather or collect in the dictionary definition of the words. The error in the example is for someone to say "I accumulate things" instead of "I collect things." This sounds wrong, because despite the denotation of the word, the most common connotation of accumulate is that a process done over time and without intent. Water accumulates. Dust accumulates. Money accumulates. But a person cannot say they accumulate things, because that is not a natural usage of the word.
However! As a writer who likes to learn new words, you can now use this knowledge to your advantage. Consider the following sentences:
Bob collected unread books until they piled high around his bed.
Books accumulated around Bob's bed, turning it into a fortress of unread words.
Both sentences are telling us the same thing - but the latter gives us a bit more insight on Bob, in that he's not intentionally obtaining so many books and not reading them, and that's a far more interesting thing to learn. The more you learn these words in context, the more you can use them to enrich your own writing. Embrace the thesaurus - but pay attention to those example sentences and how those words are actually used!