foot in the door

(n) phr., informal. The first step toward getting or doing something; a start toward success; opening.

Example: Don’t let Jane get her foot in the door by joining the club or soon she’ll want to be president.

Source: Handbook of Commonly Used American Idioms, 3rd Edition

foam at the mouth

(v) phr., slang. To be very angry, like a mad dog.

Example: By the time Uncle Henry had the third flat tire he was really foaming at the mouth.

Source: Handbook of Commonly Used American Idioms, 3rd Edition.

chew out

(v) slang. To scold roughly

Example: The couch chews out lazy players.

Source: Handbook of Commonly Used American Idioms, 3rd Edition

a bit

(n) informal. A small amount; some.

Example: if the ball had hit the window a bit harder it would had broken it.

Source: Handbook of Commonly Used American Idioms, 3rd. Edition.

abide by

(v) to accept and obey; be willing to follow.

Example: The new members agreed to abide by the rules of the club.

Source: Handbook of Commonly Used American Idioms, 3rd Edition.

stick around

(intr, adverb) Informal to remain in a place, esp awaiting something

Source: The Free Dictionary by Farlex

Slang

is the use of highly informal words and expressions that are not considered standard in the speaker's dialect or language. Slang is often highly regional, specific to a particular territory.

Slang terms are frequently particular to a certain subculture, such as musicians, and members of minority groups. Nevertheless, usage of slang expressions can spread outside their original arenas to become commonly understood, such as "cool" and "jive". While some words eventually lose their status as slang, others continue to be considered as such by most speakers. In spite of this, the process tends to lead the original users to replace the words with other, less-recognized terms to maintain group identity.

Source: www.wikipedia.com