terra firma
From Longman Dictionary of Contemporary Englishterra firmater‧ra fir‧ma /ˌterə ˈfɜːmə $ -ˈfɜːr-/ noun [uncountable]
LAND/GROUNDland, rather than sea or air – used humorously
We were glad to be back on terra firma.Examples from the Corpusterra firma• The rain seeps down through the snow and forms a bit of terra firma when the temperature plummets.• Their celestial explorations are firmly rooted where they are, on terra firma.• We were glad to be back on terra firma again.Origin terra firma (1600-1700) Latin “firm land”