"Un apter" is not a correct spelling of any word in English. It appears to be a phonetic transcription of the phrase "not apter," which should be spelled as "un-apter." The hyphen indicates that the prefix "un-" is attached to the word "apter" to create a new word with a different meaning. "Apter" can be pronounced as /ˈæp.tər/ in IPA phonetic transcription, while "un-apter" would be pronounced as /ʌn ˈæp.tər/. Always be sure to spell words correctly to avoid confusion in written communication.