maintain

To keep up or carry on; continue.

To keep in an existing state; preserve or retain.

To keep in a condition of good repair or efficiency.

To provide for; support.

To keep in existence; sustain.

To defend or hold against criticism or attack.

To declare to be true; affirm.

To adhere or conform to; keep.

To hold in an existing state or condition; keep in existence or continuance; preserve from lapse, decline, failure, or cessation; keep up: as, to maintain an upright attitude; to maintain a conversation.