PRIMITIVE
(A form (or expression) in a spoken language is a conventional pairing of a sound shape and a content, i.e. meaning or discourse function or grammatical function.)
Instead of "a form", one may also say "an expression". These terms refer to the same concept, but longer forms (such as nominal phrases or clauses) are usually called "expressions". Note that "form" is often used for the signans of a linguistic sign, and signs are said to have a "meaning" component and a "form" component. For this latter sense, it is better to use "shape" if one wants to be very precise. —— In Croft (2022), the term "element" is used roughly in this sense.
element (CXN) = a word or construction that is part of – that is, functions in a role in – a construction. Example: in an ancient watch, the elements are an, ancient, and watch. (Section 2.2.1)