Pronunciation: [ʌnbˈaləst] (IPA) 
The word "unballast" means to remove ballast from a ship to make it lighter. Its spelling follows the usual English convention of adding the prefix "un-" to the word "ballast". The word is transcribed as /ʌnˈbæləst/ in the International Phonetic Alphabet. The stress is on the second syllable, and the vowels are pronounced as /ʌ/ (as in "cup"), /æ/ (as in "cat"), and /ə/ (as in "a" or "uh").
The word "unballast" is derived from the combination of the prefix "un-", meaning "not" or "reverse", and the noun "ballast". "Ballast" comes from the Old Swedish word "ballest", which means "load" or "cargo". It then entered Middle Low German as "ballast" and Middle Dutch as "balgast". The term eventually made its way into Middle English as "ballast" with the same meaning of stabilizing weight carried by a ship to improve stability.
The prefix "un-" added to "ballast" creates "unballast", which signifies the removal or absence of ballast.
