noun

• A protein-rich food made from curdled soy milk.
• (computing, typography) A box or rectangle, empty or with a question mark or hexadecimal code inside, displayed by some systems in place of a character not supported by available fonts. (such as _□ or 𐕪)
• (networking) Initialism of trust on first use, a type of network software security model where a client requests an identification code from a remote host when establishing the first connection.
• (marketing) Initialism of top of funnel.