sostener
/sosteˈneɾ/ · B1 · verb
to hold, to hold up, to prop up, to sustain, to underpin
🏗️ sostener = sos (under) + tener (to hold): hold from below, like sustain
From Latin sustinere: sub (under) + tenere (to hold). English sustain is the same word, so sostener = sustain. It conjugates like tener: sostengo, sostiene, sostuve. Holding up a wall and holding up an argument use the same verb.