A density threshold cannot make the decision
Google defines keyword stuffing as filling a page with keywords or numbers in an attempt to manipulate rankings, often in lists, groups, or unnatural repetition. Its policy describes behavior and intent, not a percentage.
A medical reference may legitimately repeat a precise term. A location landing page may be stuffed while staying below an arbitrary density threshold. Count can flag a passage for review, but it cannot determine whether each use does work.
Look for sentences that exist only to carry variants
Consider this pattern: “Our Lisbon SEO company provides Lisbon SEO services from Lisbon SEO experts for businesses seeking Lisbon search engine optimisation.” Each phrase names nearly the same thing. Removing most of them loses no information.
The same defect appears as city blocks, long synonym strings, invisible or tiny text, repeated headings, and footers listing every service-location pairing. It also appears in polished prose when every paragraph restates the target phrase without adding evidence, reasoning, or a decision.
Repair the information architecture before polishing
If multiple pages differ only by a swapped phrase, decide whether they own genuinely different reader jobs. Merge duplicates and redirect only where the surviving page truly takes over the old job. A rewrite cannot give twenty interchangeable URLs independent purpose.
Inside a valid page, replace enumerations with the actual category, then restore individual terms only where their differences matter. Use the reader's vocabulary naturally in the title, heading, explanation, and examples. The keyword is allowed to be visible; the page simply needs more to say than the keyword.
Verify the repaired page in context
Read the page aloud, inspect headings and navigation, and search the rendered text for repeated sequences. Then ask what new information every paragraph adds. If a paragraph contributes no evidence, reasoning, consequence, decision, or necessary transition, removing it is usually more useful than finding a synonym.
Google's policy makes the anti-pattern clear. The harder editorial test is whether the surviving copy teaches the reader something they could not get from the phrase itself.