Also borrowed from another site

a list of CR slang
-mae (my): Mae can be used to mean "dude" between friends, or simply to refer to any man or woman ("ese mae te esta llamando" = "that guy is calling you").
-100 (cien) metros (see-en met-ros): Always remember that "cien metros" means "one block." Likewise, "doscientos (200) metros" means "two blocks," and "cincuenta (50) metros", "half a block" – all regardless of the actual length of the block.
-aguevado (ah-gway-va-doh): bored or boring (synonym of bostezo)
-bostezo (boh-stes-oh): bored or boring (a synonym of aguevado)
-apuntarse (ah-poon-tar-say): to sign up (for something, like a tour)
-brete (bre-tay): work or job
-como amanecio? (coh-moh ah-mahn-es-ee-oh): how are you this morning?
-chunche(choon-chay): thingamajig
-di/diay(dee/dee-ay): With no exact translation, diay is best thought of as an interjection at the beginning of a sentence, similar to "um" or "well."
-dolor de jupa (dole-or day hoop-ah): a headache
-el chante (el chahn-tay): home (house
); place
-estar de chicha(es-tar day chee-chah): to be angry
-estar de goma (es-tar day goh-mah): to have a hangover
-fijate/fijese(fee-hah-tay/fee-hey-say): Another phrase with no exact translation, this is best thought of as an interjection, approximately meaning "would you believe it?"
-guila(gwee-lah): Despite its meaning in Mexico, a guila in Costa Rica is merely a "girl."
-hijueputa (ee-who-ay-poo-tah) (vulgar): son of a bitch
-la jama (lah hah-mah): food
-jamar (hah-marh): to eat
-jumas (hoo-mahs): drunk
-la choza (lah choh-sah): home
-que mala nota! (kay mahl-ah no-tah): what a bad person!
-macha (mah-cha): a blond female, usually a foreigner
-mucho gusto (moo-choh goo-stoh): Translating directly as "[with] much pleasure," Costa Ricans use this in lieu of "de nada," or "thank you."
-no entender ni papa (no en-ten-der nee pah-pah): to not understand a word
-no joda!/no jodás!(no hoe-da/no hoe-das): don't bother me! / leave me alone!
-ojo! (oh-hoe): watch out!
-pura paja(poor-ah pa-hah): crap; bullshit
-pinche (peen-chay): Despite its meaning in Mexico, pinche means "stingy" in Costa Rica.
-por dicha(poor dee-chah): thank goodness
-pulperia(pool-pehr-ee-ah): a small corner store
-que m'iche? (kay mee-chay): what's up? / what do you have to tell me?
-que pereza!(kay pay-ray-sah): ugh, what a drag! (synonym of "que tigra!")
-que tigra! (kay tee-grah): ugh, what a drag! (synonym of "que pereza!")
-salado (sahl-ah-doh): unlucky
-soda (soh-dah): a small, family-run typical restaurant
-soque!(soh-kay): hurry up!
-una teja (oo-nah tay-hah): Una teja is 100 of anything, usually money (100 colones). If someone is giving you directions, however, una teja refers to "100 meters," or one block.
-tome chichi!(toe-may chee-chee): Though this phrase has no direct translation, it's essentially a teasing form of "take that!"
-tuanis(too-ahn-ees): Said to be a Spanish adaptation of "too nice," this popular phrase means "cool."
-va jalando!(bah hahl-ahn-do): get out of here! / go away!
-la vara (lah bar-ah): the thing
-upe! (oo-pay): hello? anyone home?
-vieras que/viera que (bee-air-ahs kay/bee-air-ah kay): Another Costa Rican idiom with no direct translation, "vieras que/viera que" means "sure", in the sense of "I sure was surprised by his apology!" ("Vieras que sorprendida me dejo su disculpa!")