keep in safety and protect from harm, decay, loss, or destruction; "We preserve these archeological findings"; "The old lady could not keep up the building"; "children must be taught to conserve our national heritage"; "The museum curator conserved the ancient manuscripts"
If you maintain a road, building, vehicle, or machine, you keep it in good condition by regularly checking it and repairing it when necessary. The house costs a fortune to maintain The cars are getting older and less well-maintained. = look after
If you maintain something, you continue to have it, and do not let it stop or grow weaker. The Department maintains many close contacts with the chemical industry
If you say that someone maintains that something is true, you mean that they have stated their opinion strongly but not everyone agrees with them or believes them. He has maintained that the money was donated for international purposes `Not all feminism has to be like this,' Jo maintains He had always maintained his innocence. = claim
To continually test, debug, and modify a program so as to fix bugs and otherwise ensure that it continues to work reliably (e g , in the face of changes to its environment, to its requirements, or to the underlying system)
keep in a certain state, position, or activity; e g , "keep clean"; "hold in place"; "She always held herself as a lady"; "The students keep me on my toes"