each essence is distinguished from the other. It is then equivocal, as in lexical homonymy. Alternatively, it may be applied with reference to what the two essences have in common, in which case it is a univocal term.”

I say:

A term may originally be assigned in the language to denote the common element; customary usage then comes predominantly to apply it now to one, now to the other. Thus, by customary usage, it comes to signify both what they share and what distinguishes them.

The distinguishing feature may instead be indicated by a contextual marker, such as the definite article or a possessive construction. An example is a generic term whose customary usage has come to refer predominantly to certain species within its scope. Thus, when the word “animal” is used predominantly for a horse, we may apply it to a horse with reference to what it shares with all other animals. In that case, it is univocal.

We may also apply it with reference to what is specific to a horse. In that case, it is equivocal between horses in particular and animals in general. Its application to a horse is therefore sometimes univocal and sometimes equivocal.

The same applies when a generic term comes to refer predominantly to particular individuals and becomes a proper name through predominant usage, as with “the son of ‘Amr” and “the star.” We may apply the term to the individual with reference to what he or it shares with the other sons of ‘Amr or the other stars. Its application is then univocal. We may also apply it with reference to what distinguishes that individual from the other sons of ‘Amr or the other stars. It is then equivocal between this individual sense and the generic sense. Likewise, every general term whose use has come to predominate for certain individual instances