Negative keywords
Definition
Negative keywords are terms an advertiser adds so that ads don't show on searches containing them, cutting wasted spend. Google says they don't match close variants, so plurals and synonyms must be added separately.
Negatives come in broad, phrase and exact types. A broad negative blocks a search only when it contains all of the negative's words, in any order. A phrase negative needs them in order, and an exact negative blocks only that precise search. Because they don't expand to related forms, a negative for 'free' doesn't cover 'complimentary', so the list grows from evidence, not guesswork.
Build the list from the search terms report, and add each language you advertise in: an Arabic-script negative can't block the same word typed in Latin letters, so transliterated versions are separate entries. Start with job-seekers, bargain-hunters and competitors' names, then review monthly. Check each new negative against your own good customers before adding it, because 'cheap' might be exactly what your best-converting buyers type.
Definitions are free.So is the cost review.
A short call, then a written review inside 72 hours: what your marketing costs, what it produces, and what is worth fixing first.