One of the point-by-points summaries indicated that a zav is one who experiences a seminal emission. I have always been under the impression that they are two different physical manifestations, that a zav is a male who experiences a gonorrheal emission. Can you please clarify?
You are absolutely correct. The emission of Zav and that of Keri are two entirely different things. A Zav is a man who experiences something akin to a gonorrheal emission, as you mentioned. Below is what we wrote in the Daf- Background section to Megilah Daf 8a (the first paragraph, (a), is what is relevant to your question).
6) [line 20] ZAV
(a) A Zav, a man who emits Zov two or three times (see Background to Shabbos
84:1), whether it is emitted in one day or in two or three consecutive days,
is an Av ha'Tum'ah. Zov is a clear discharge with the appearance of the white
of a sterile or spoiled egg, in contrast with semen, which has the
consistency of fresh egg white (Nidah 35b). Zov can also be a pus-like
discharge resembling the liquid from barley dough or soft barley batter.
(b) A man who emits a discharge that may be Zov is "checked " to determine
whether or not he becomes a Zav. If the discharge came about b'Ones (due to
an external cause), he is Tahor. Some examples of Ones are: 1. eating too
much; 2. drinking too much; 3. jumping; 4. being sick; etc. (see Zavim 2:2).
(c) A Zav must count seven "clean" days in which he sees no Zov in order to
start his purification process, as it states in Vayikra 15:13. On the seventh
day or afterwards, he must immerse in a spring during the day . At nightfall
he becomes Tahor, if he did not emit Zov again beforehand (ibid.).
(d) If a Zav emits Zov only two times, he does not bring a Korban. If he
emitted Zov three times, whether it is emitted in one day or in two or three
consecutive days, he has to bring a Korban after he becomes Tahor in order to
enter the Beis ha'Mikdash and to eat Kodshim and Terumah. The Korban is two
Torim (turtledoves) or two Benei Yonah (common doves), one offered as an Olah
and one as a Chatas.