What is the correct term for pleonasm?

Is there more complete pleonasm than it is necessary to know the full truth? Examples are dark darkness, or burning fire.

Wikipedia. Source. *

They can also be generically termed as intensifiers. All intensifiers are redundant but add clarity. Is there a term for “Intensive” specifically it’s the same word used twice in a single cell?

In a paper on the exact construction by Ghomeshi and al (2004), it’s called contrastive focus reduplication. Natural Languages & Linguistic Theory 22: 307–357, 2004.

EDIT
The paper is 52 pages long, the following extracts are taken from the first 8 pages long.

ENGLISH SUSPENSION: CONTRASTIVE FOCUS REDUPLICATION
(THE SALAD-SALAD PAPER)

ABSTRACT. This paper presents a phenomenon of colloquial English that we call Contrastive Reduplication (CR), involving the copying of words and sometimes phrases as in It’s tuna salad not Salad-salad, or Do you LIKE-him-like him? Drawing on a corpus of examples gathered from natural speech, written texts, and TV scripts, we demonstrate that CR restricts the interpretation of the copied element to a’real’ or prototypical reading. g)

Examples of this construction are

(1)a. h. (a). I’ll make the tuna salad, you make the salsa. Thanks! What
is LIKE, EM-like EM? I want to pay store credit for a certain amount (more than $100) but I don’t have any. Or, I’d like to get store credit. What?? 2 c.
Is he a French or French-French?
b. D. D. O. R. O. E. B., P. I. T. I. V I’m not UP-up. I am up, I’m just not UP. ()
e. What does it feel like? f.
n. My car isn’t mine, it’s my parents’.
g. g. r. g. g. g. We are not all part together. Uh oh we’re not all life together.

(…)

The semantic effect of this construction is to focus the denotation of the reduplicated element on a more sharply delimited, more specialized, range. In the context in which (1e) was used, AUCKLAND–Auckland denotes the city in New Zealand as opposed to other cities that may happen to have this name.
(…) This leaves open some vagueness, lack of precision, or ambiguity. CR is used as one way to clarify such situations, by specifying a prototypical denotation of the lexical item in contrast to a potentially more specialized reading. This is clearest when applied to simple nouns: )((B.)#)/(E.)(e.)((e.)(i.)((e.)(p.h.: I.)(L.V.)

(3) c. She wasn’t a fancy cow, a Hereford or Black Angus or something, just a cow. (…)

(…)

This characterization is precisely the informal one given by Horn (1993). He briefly discusses CR (which he labels, following Dray (1987), the ‘double construction’) stating: “As a rough approxroximation, we can say that an expansion of noun is absent. (JG et al., 1995)” ] A: They said that. They were talking about non–nervous, not nervos. They were… , not “really” nervous]]
(…) Lawrence Horn (p. 1357) (ibid.) c.), in further recent work on CR (which he now calls’lexical cloning ‘), categorizes the semantics of this construction into four types: (a) prototype meaning (which we have already discussed), (b) literal meaning, (c) intensified meaning, and (d) ‘value-added’ meaning. An example of literal meaning appears in (12), where reduplication signals that a literal and rather than euphemistic interpretation of coming in for coffee is

intended: (12)
A: How can I have a coffee at the AAP?
Why don’t we like it too?
A: Just coffee-coffee, no double meanings for “coffee” – a classic coffee, no double meanings for chocolate – for chocolate and not coffee (for caffeine). ?