Dejong is a Dutch surname that is phonetically spelled as /dəˈjɔŋ/. The initial "d" sound is pronounced as a voiced dental fricative, while the "e" sound is pronounced as a schwa. The "j" sound is pronounced as a palatal approximant, similar to the "y" sound in "yes". The "o" sound is pronounced as a mid-back rounded vowel, and the "ng" at the end of the word is pronounced as an ŋ sound. Overall, the spelling of Dejong follows the rules and sounds of the Dutch language.
There is no known widely recognized etymology for the word DeJong. However, it can be speculated that DeJong is a Dutch surname, as De Jong is a common Dutch surname translating to The Young. It is possible that DeJong could be an anglicized or alternative spelling of the Dutch surname De Jong.