esto
/ˈesto/ · A1 · pron
substitutes a noun one can't remember or can't remember the name of
esto = this; Latin istud, kin to este/esta, the neuter for unnamed things
Esto is the neuter form of este/esta, from Latin istud. Spanish nouns are never neuter, so esto cannot point at a named noun: it stands in for a thing whose name you lack or have forgotten. Sound hook: esto sounds like S-toe.