The term 'completely developed' can be described by two crossword solutions: ADULT (5 letters) and FULLFLEDGED (11 letters). An ADULT is a person who has reached the age of majority, typically 18 years old, and is considered to be fully grown and mature. A fullfledged individual is someone who has achieved a high level of development, usually in terms of skills, knowledge, or experience. Therefore, the term 'completely developed' can be used to describe an individual who has reached adulthood and has achieved a high level of development.