Open Google Chrome
Click the three-dot menu (top-right)
Select History
Click History again
Click Clear browsing data
Select the time range (choose All time to clear everything)
Check Browsing history (and optionally Cookies and other site data and Cached images and files)
Click Clear data
To delete only Google Search suggestions: go to https://myactivity.google.com
Sign in to your Google account
On the left, select Delete activity by
Choose All time (or a custom date range)
Select Search
Click Delete
To delete individual past searches: go to https://myactivity.google.com
Find the search item
Click the trash/delete icon
To clear search suggestions on the Google app (Android/iOS):
Open Google app
Tap your profile picture
Tap Settings
Tap Privacy
Tap Clear search history