Maintain is a versatile English verb with multiple meanings:
1. To keep in an existing state (e.g., "maintain good health")
2. To sustain or provide for (e.g., "maintain a family")
3. To keep in good condition (e.g., "maintain a car")
4. To assert or declare (e.g., "he maintains his innocence")
5. To defend or uphold (e.g., "maintain one's position")