I am sure this has been explained before, but here is a not-so-brief summary:
"Voice" (φωνή) is a morphological category in Greek. Verbs either end in -ω in their dictionary form (1st person singular present indicative) or in -μαι. The former are in the active voice (ενεργητική φωνή), the latter in the passive (also called middle or medio-passive) voice (παθητική, μέση, μεσοπαθητική φωνή). Their whole conjugation depends on that. Similarly, nouns have grammatical gender - meaning that they take a particular article (ο, η, or το), that they are accompanied by suitable forms of the adjective (άσπρος βράχος, άσπρη πέτρα, άσπρο χαλίκι) etc. , and their declension depends on their gender.
Now, those grammatical categories are loosely correlated with semantic categories. Gender is loosely correlated with sex: nouns denoting male humans and animals are usually masculine in gender, nouns denoting female humans and animals are usually feminine in gender, nouns denoting inanimate things tend to be neuter in gender. And some nouns have both masculine and feminine forms, respectively denoting similar animate beings differing only in their sex: βασιλιάς/βασίλισσα, μαθητής/μαθήτρια, γάτος/γάτα... But of course, this is only a loose correlation -- αγόρι and κορίτσι are neuter, τοίχος and στέγη are masculine and feminine respectively, and βάτραχος or μύγα, though masculine and feminine respectively, in no way imply a definite sex.
Similarly, most verbs signifyng an action done by the grammatical subject to someone or something belong to the active voice and have a correlative passive form signifying that the action is done to the grammatical subject, either by itself or by somebody or something else: thus, πλένω = Ι wash (something) and πλένομαι = Ι wash myself or I am being washed (τα ρούχα πλένονται στο πλυντήριο). The semantic relationship of the verb to its grammatical subject is traditionally called diathesis (=disposition) in Greek grammar, and four such diatheses are recognized: active, where the subject performs the action (I am eating an apple; I am running), middle, where the subject does something to or for itself (I am shaving (myself)), passive, where the subject undergoes the action (I am being shaven by the barber), and neutral, where no action is performed (I am sleeping; ασθενώ = I am sick). The reason why traditional grammar bothers with diatheses is that in Ancient Greek, the future and aorist (only) had different forms depending on whether the diathesis was middle or passive. Thus, λύομαι meant both "I untie myself" and "I get untied by somebody else", but in the aorist tense "I untied myself" was ελυσάμην and "I gοt untied by somebody else" was ελύθην! (This is a gross oversimplification; the 'middle' forms could express all sorts of subtle shades of meaning that often escape us moderns, but the passive diathesis forms were usualy truly passive in meaning.) The 'middle' forms have totally disappeared from modern Greek, leaving no traces except in the confusion of the terms denoting the passive voice.
But just as grammatical gender of nouns only has a loose correlation with sex, so also does voice of verbs only have a loose correlation with diathesis. To be sure, the active verb ζεσταίνω does mean 'to heat something up', while its passive counterpart ζεσταίνομαι neans 'to get warm' or 'to feel hot'; but the antonym κρυώνω has no passive form (there is no *κρυώνομαι!) and means both 'to cool something' and 'to feel cold'. Similarly, καθυστερώ means both 'to delay someone' and 'to be delayed', and there is no *καθυστερούμαι. And more importantly, there are a good many verbs that only exist in the passive voice: έρχομαι, δέχομαι, σκέπτομαι, εργάζομαι, φοβάμαι, ονειρεύομαι, εκμεταλλεύομαι... Some of those verbs are even transitive (i.e. express an action doe to somebody or something), and one has to resort to synonyms or circumlocutions to express what in English would be expressed by the passive construction: 'to be accepted' is γίνομαι δεκτός, 'to be exploited' is πέφτω θύμα εκμετάλλευσης, 'to be processed' is υφίσταμαι επεξεργασία etc., as amply explained in revious comments.
Βαριέμαι is one of these 'deponent' (αποθετικά) verbs, which only exist in the passive voice without being passive in meaning.
The perfect participle of deponent verbs is sometimes used in a passive sense: επεξεργασμένος means 'processed', παραδεδεγμένος (from παραδέχομαι, with reduplication) means 'generally accepted', ονειρεμένος means 'dreamed of'. Βαρεμένος, hoever, does not mean 'bored' (βαριεστημένος would be the closest single-word equivalent); it means 'stricken', and, in Cretan dialect, 'pregnant'!
There are no example of use... I suppose it's better not to think of using καταδικάζω as 'to damn'.
