In order to delete search history from the
gmail app tap on the “Gmail” app. Tap on menu. Tap on “settings”. Select “General settings”. Tap on the three dotted menu. Now select “Clear search history”. Select “Clear”. Also if you want to delete the search history
from all the devices then tap on “Gmail” again. Tap on the menu icon. Select “Settings”. Select the gmail account whose searches you
want to delete from all the devices. Select “Manage your google account”. Select “Personal info & privacy”. Scroll down and select “Activity controls”. Select “Web & App activity’. Now select “Manage activity”. Now tap on the three dotted icons right to
“Search web & App”. Now select “Delete Activity by”. Now you have to select the date. You want to delete the searches for today
or you want to delete the searches for last 30 days. I will select “All time” and then select “Delete”
and then select “Delete” again. Now the google search history should be cleared
from all the devices.