Protect:
To keep safe; to defend; to guard; to prevent harm coming to.
http://en.wiktionary.org/wiki/Protect
to defend or guard from attack, invasion, loss, annoyance, insult, etc.; cover or shield from injury or danger.
http://www.infoplease.com/dictionary/protect
cover for -- (provide an excuse or alibi for someone so as to cover up guilt; ``I won't lie and cover for you'' )
immunize, immunise -- (law: grant immunity from prosecution)
overprotect -- (protect excessively; ``Don't overprotect your son--he is an adult now!'' )
look out -- (to protect someone's interests; ``A man's gotta look out for his family'' )
cover -- (hold within range of an aimed firearm)
guard, ward -- (watch over or shield from danger or harm; protect; ``guard my possessions while I'm away'' )
defend, guard, hold -- (protect against a challenge or attack; ``Hold that position behind the trees!"; "Hold the bridge against the enemy's attacks'' )
shield, screen -- (protect, hide, or conceal from danger or harm)
charm -- (protect through supernatural powers or charms)
wall, palisade, fence, fence in, surround -- (surround with a wall in order to fortify)
safeguard -- (make safe)
cover -- (protect or defend (a position in a game); ``he covered left field'' )
cover -- (be responsible for guarding an opponent in a game)
mothproof -- (protect from moths; ``mothproof woollen clothes during the summer'' )
body guard -- (accompany and protect from physical harm)
insure -- (take out insurance for)
cover -- (to take an action to protect against future problems; ``Count the cash in the drawer twice just to cover yourself'' )
Preserve
1. to keep alive or in existence; make lasting: to preserve our liberties as free citizens.
2. to keep safe from harm or injury; protect or spare.
3. to keep up; maintain: to preserve historical monuments.
4. to keep possession of; retain: to preserve one's composure.
5. to prepare (food or any perishable substance) so as to resist decomposition or fermentation.
6. to prepare (fruit, vegetables, etc.) by cooking with sugar, pickling, canning, or the like.
7. to maintain and reserve (game, fish, etc.) for continued survival or for private use, as in hunting or fishing.
http://www.infoplease.com/dictionary/preserve
1. [v] keep or maintain in unaltered condition; cause to remain or last; "preserve the peace in the family"; "continue the family tradition"; "Carry on the old traditions". More...
2. [v] to keep up and reserve for personal or special use: "save something in case you hit trouble.". More...
3. [v] keep in perfect or unaltered condition; "We preserve these archeological findings"; "The old lady could not keep up the building". More...
4. [v] to keep up and reserve for personal or special use; "She saved the old family photographs in a drawer". More...
5. [n] a domain that seems to be specially reserved for someone; "medicine is no longer a male preserve". More...
6. [v] prevent from rotting, of foods; "preserved meats"; "keep potatoes fresh".
http://lookwayup.com/lwu.exe/lwu/d?s=f&w=preserve