Which will ofcourse lead you to keyword stuffing, and eventually, google will ban you.
meta keywords are no longer used by google, which is main search engine, not quite sure, but none of modern search engines use them anymore.
Keywords should have to be related to each other, for example, if you have porn site, related keywords would be: free porn download, porn download links, watch porn movies...etc
Don't repeat same keywords in every post, google penalize that.
Make other long tail keywords, make backlinks using them, on relevant sites, with same keywords.
Example, if you want to rank for term: watch porn movies, make sure, you have it in title of the post, on the beginning of the post some long tail keyword including that particular phrase, like here you can watch free porn movies through our integrated web player blahblah.... , then, make some sentence at the end of article, making some variation of it. It must look natural. Don't ALWAYS repeat same pattern.
When you do backlinking for that page, make sure you are linking from relevant site, that is ranked high for that keyword, watch free porn, with wanted description, ofcourse, and link to that post. That's SEO, as simple as it can be explained in few sentences...
What you actually want to do, is research for keywords, to find out which isn't saturated, but still brings traffic, and is possible to relatively easy to rank for.
If one longtail keyword brings monthly 5000 searches, catch is to find as many as you can, such keywords, that are relative to your website,and relative to each other, and rank high for every of them. Not only for one. You want more than one cookie.
