I am studying Aristotle's views on substance, and in the narratives of his work, the term 'predicated' is used with great frequency, though not at all defined. In Googling the meaning of 'predicated', I get this:
Predicated: 'state, affirm, or assert (something) about the subject of a sentence or an argument of a proposition'
However, I had no idea what 'subject' means, upon research, it seems to be that which is the reason for existence of a sentence i.e a noun for e.g 'sky' in the 'sky is blue', the subject at hand is sky, to which it is blue. Anyway, I could be wrong, and even if not I still don't know what the subject of a sentence of a proposition is or means. I always thought a proposition was a sentence only one with assertion i.e one that is true or false. So all propositions are sentences but not all sentences are propositions. So this just adds to the confusion.
Furthermore, I can't draw up a connection between predicate, and what it means to be predicated. I think a predicate is a proposition with variables, so for e.g instead of 'the sky is blue', you could have 'the n is v' where n = noun, and v = verb. From this, I suppose to be predicated could mean to be variableized? Though am not at all sure.
This is the passage I have trouble interpreting:
Z.3 begins with a list of four possible candidates for being the substance of something: essence, universal, genus, and subject. Presumably, this means that if x is a substance, then the substance of x might be either (i) the essence of x, or (ii) some universal predicated of x, or (iii) a genus that x belongs to, or (iv) a subject of which x is predicated. The first three candidates are taken up in later chapters, and Ζ.3 is devoted to an examination of the fourth candidate: the idea that the substance of something is a subject of which it is predicated. (SEP entry on Aristotle's metaphysics)
On a side note, perhaps the term is just archaic?