A sigil is a symbol or sign that is used to represent a concept, often in magical or religious contexts. It is usually composed of a specific set of shapes and symbols that are meant to convey a particular meaning. The term 'sigil' comes from the Latin word sigillum, which means 'SEAL'. In this context, a SEAL is a type of mark or symbol that is used to authenticate documents or signify ownership. The crossword solutions for the term sigil are 'SEAL', which is a four-letter word.