An adult is a human being who has reached physical and emotional maturity, typically characterized by:

1. _Physical Development_: Completion of physical growth and development, including the attainment of full height, weight, and physical strength.
2. _Emotional Maturity_: Development of emotional regulation, self-awareness, and independence, enabling individuals to take responsibility for their lives and decisions.
3. _Cognitive Development_: Attainment of advanced cognitive abilities, including problem-solving, critical thinking, and decision-making.

Characteristics of Adults

1. _Independence_: Ability to make decisions, take care of oneself, and be self-sufficient.
2. _Responsibility_: Willingness to take responsibility for one's actions, decisions, and life.
3. _Self-Awareness_: Understanding of one's strengths, weaknesses, values, and emotions.
4. _Emotional Regulation_: Ability to manage and regulate one's emotions, leading to greater emotional intelligence.

Roles and Responsibilities of Adults

1. _Career and Work_: Engaging in meaningful work or career, contributing to society, and earning a living.
2. _Relationships and Family_: Building and maintaining healthy relationships, including romantic partnerships, friendships, and family relationships.
3. _Community Involvement_: Participating in community activities, volunteering, and contributing to the greater good.
4. _Personal Growth and Development_: Continuously learning, growing, and developing as individuals, pursuing hobbies, interests, and passions.

Would you like to know more about:

1. Adult development stages and transitions?
2. Strategies for maintaining physical and mental health as an adult?
3. Effective communication and relationship-building skills for adults?
4. Something else?