Definitions of inactive:

• adjective:   not in physical motion
• adjective:   not engaged in military action
• adjective:   not participating in a chemical reaction

  Example: "Desired amounts of inactive chlorine"

• adjective:   not active physically or mentally

  Example: "Illness forced him to live an inactive life"

• adjective:   not engaged in full-time work

  Example: "Inactive reserve"

• adjective:   lacking activity; lying idle or unused

  Example: "An inactive mine"

• adjective:   not progressing or increasing; or progressing slowly
• adjective:   not active or exerting influence
• adjective:   lacking in energy or will
• adjective:   of e.g. volcanos; temporarily inactive
• adjective:   of e.g. volcanos; permanently inactive
• adjective:   temporarily inactive