The spelling of the word "welth" is incorrect. The correct spelling is "wealth," which is pronounced as /wɛlθ/ in the International Phonetic Alphabet. The "th" sound is represented by the symbol /θ/, which is produced by placing the tongue between the teeth and blowing air out. "Wealth" is a noun that refers to an abundance of valuable possessions or resources. It is important to use correct spelling to communicate effectively, especially in written communication.