1. The agreement you have with someone and the help you might give them; the money and things you give to someone to help them do something. English = support, backing.
2. Things added to something else to make it stronger, especially soldiers which are sent to join an army in order to make it stronger. English = reinforcement, reinforcements.
3. Money, equipment, or services that are provided to people in need. English = aid, assistance.
4. A person who helps another person in their work. English = assistant.