shy

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Easily startled; timid.
• adjective Tending to avoid contact or familiarity with others; retiring or reserved.
• adjective Characterized by reserve or diffidence.
• adjective Distrustful; wary.
• adjective Not having a sufficient or specified amount, as of money.
• intransitive verb To move suddenly or draw back, as if startled or afraid.
• intransitive verb To avoid engaging in, treating, or discussing something.
• noun A sudden movement, as from fright; a start.
• intransitive verb To throw (something) with a swift motion; fling.
• intransitive verb To throw something with a swift motion.
• noun A quick throw; a fling.
• noun Informal A gibe; a sneer.
• noun Informal An attempt; a try.

from The Century Dictionary.

• Readily frightened away; easily startled; skittish; timid.
• Shrinking from familiarity or self-assertive-ness; sensitively timid; retiring; bashful; coy.
• Keeping away from some person or thing through timidity or caution; fearful of approaching; disposed to avoid: followed by of.
• Cautious; wary; careful: commonly followed by of or about.
• Elusive; hard to find, get at, obtain, or accomplish.
• Morally circumspect; scrupulous.
• Keen; piercing; bold; sharp.
• Sly; sharp; cunning.
• Scant. The wind is said to be shy when it will barely allow a vessel to sail on her course.
• Synonyms Diffident, shamefaced. See bashfulness.
• To shrink or start back or aside, as in sudden fear: said specifically of a horse.
• To avoid; shun (a person).
• noun A quick, jerking, or careless throw; a fling.
• noun A fling; a sneer; a gibe.
• noun A trial; an experiment.
• To fling; throw; jerk; toss.
• To throw off; toss or send out at random.
• To throw a missile; specifically, to jerk.
• Hence, in general, to lack; be short of: as, to be shy four dollars.
• noun In cricket, a ball thrown instead of bowled.
• noun A sudden start aside, as from fear, especially one made by a horse.

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb To start suddenly aside through fright or suspicion; -- said especially of horses.
• transitive verb To throw sidewise with a jerk; to fling.
• noun A sudden start aside, as by a horse.
• noun A side throw; a throw; a fling.
• adjective Easily frightened; timid.
• adjective Reserved; coy; disinclined to familiar approach.
• adjective Cautious; wary; suspicious.
• adjective Slang Inadequately supplied; short; lacking.
• adjective (Poker), Slang owing money to the pot; -- in cases where an opponent's bet has exceeded a player's available stake or chips, but the player chooses to continue playing the hand before adding the required bet to the pot.
• adjective See under Fight, v. i.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Easily frightened; timid.
• adjective Reserved; disinclined to familiar approach.
• adjective Cautious; wary; suspicious.
• adjective Short, insufficient or less than.
• adjective Embarrassed.