I read Hacker News through hckrnews.com and accomplish the same thing with a single line in my ad blocker browser extension (uBlock) filter list.

Here's an example of the filter:

hckrnews.com##.entry:has-text(/(orange|pineapple|kiwi)/i)

Or it could be written as multiple lines if that looks cleaner:

hckrnews.com##.entry:has-text(/orange/i)

hckrnews.com##.entry:has-text(/pineapple/i)

hckrnews.com##.entry:has-text(/kiwi/i)