LATIN DICTIONARYLexicon Latīnum
adverb

istūc

istūc (not comparable)
Classical[ɪsˈtuːk]Ecclesiastical[isˈtuk]

Meaning

  1. not comparableto or towards the place where you are, which you mention
    Jam ego istūc revortar, mīles.I'm about to return there, warrior.c. 195–189 BCE, Titus Maccius Plautus, Poenulus:
  2. not comparableto the point in a discourse that you have reached or mentioned
    Gnaeus quidem noster jam plānē quid cōgitet nesciō [..] quī quidem etiam istūc addūcī potuerit.But what our friend Gnaeus is thinking I simply don't know any more [..] that he ended up allowing such a measure as this.59 BCE 29 April, Marcus Tullius Cicero, Letters to Atticus:

istuc, adv. isto- (iste) ce,
I. thither, esp. in reference to the place where the party addressed is: concedite istuc, Plaut. As. 3, 3, 56: istuc eo quantum potest, id. Merc. 4, 1, 25: jam istuc ego revortar, id. Poen. 3, 3, 1; Ter. Eun. 4, 4, 39: dabam operam, ut istuc veniam ante quam plane ex animo tuo effluo, Cic. Fam. 7, 14, 1: istuc mens animusque Fert, Hor. Ep. 1, 14, 8: dum transferor istuc, Ov. H. 18, 205.—
II. Transf., to that thing, to that subject in discourse, etc.: hoc quod coepi primum enarrem: Post istuc veniam, Ter. Heaut. 2, 3, 33: scio: istuc ibam, id. Ad. 5, 3, 35.

Quick answers

What does istūc mean in Latin?
istūc, a adverb, means “to or towards the place where you are, which you mention; to the point in a discourse that you have reached or mentioned”.
How do you pronounce istūc?
In classical Latin, [ɪsˈtuːk]; in ecclesiastical (church) Latin, [isˈtuk].