An assumed zero value of a quantity relative to which magnitudes of the quality are measured, or a structure having this zero value of the quantity; e g , a voltage measured relative to the ground as a referent
1 Something that refers, especially a linguistic item in its capacity of referring to a meaning; 2 Something referred to
something that refers; a term that refers to another term the first term in a proposition; the term to which other terms relate something referred to; the object of a reference