to keep in existence or continuance; preserve; retain

to maintain good relations with neighboring countries.

to keep in an appropriate condition, operation, or force; keep unimpaired

to maintain order; to maintain public highways.

to keep in a specified state, position, etc.

to maintain a correct posture; to maintain good health.

to affirm; assert; declare

He maintained that the country was going downhill.

to support in speech or argument, as a statement or proposition.

to keep or hold against attack

to maintain one's ground.

to provide for the upkeep or support of; carry the expenses of

to maintain a family.

to sustain or support

not enough water to maintain life.