"Derangeds" is not a correct spelling in English. The correct spelling is "deranged", pronounced as /dɪˈreɪndʒd/. The IPA transcription shows the stress on the second syllable /reɪndʒ/ and the final consonant cluster /dʒd/ which is a combination of a stop consonant /dʒ/ and a non-syllabic voiced alveolar fricative /d/. The word "deranged" means to be mentally unbalanced or insane, and it is widely used in psychology and psychiatry.
Deranged is derived from the verb derange, which originated from the French word déranger. The word déranger can be broken down into two parts: dé- (meaning to reverse) and ranger (meaning to organize or to arrange). Therefore, déranger initially carried the sense of to disturb or to upset the order. Over time, the term deranged emerged in English to describe a state of mental disturbance or insanity. The plural form of deranged is simply derangeds.