The word "unsuddenly" may seem confusing and contradictory at first glance, but its spelling and pronunciation can be easily explained through phonetics. The "un-" prefix denotes negation or reversal, while the "suddenly" root word is pronounced /sʌdnli/. Thus, the correct phonetic transcription of "unsuddenly" is /ʌn'sʌdnli/. This word is used to describe something that does not occur suddenly or unexpectedly. Although it may not be a commonly used word, it provides a concise way to express the opposite of suddenness.
The word "unsuddenly" does not have an established etymology as it is not recognized as a standard English word. It seems to be a combination of the prefix "un-" (meaning not) and the word "suddenly" (meaning abruptly or unexpectedly).