what's the practical way to exclude words from google search?

Works for sites too: -site:pinterest.com clears a whole domain out. And if Google keeps swapping in synonyms or ignoring part of your query, go to Tools under the search box and switch All results to Verbatim.

Minus sign directly in front of the word, no space: jaguar -car. For a phrase, put it in quotes after the minus: -"free trial". You can stack as many as you like. If the word still turns up, the page usually has it somewhere you are not looking, like a footer or the comments.