An "idiom" can be slang, but it can also be a metaphor that becomes part of the culture.
ʌ n WORD_BOUNDARY ɪ d ɪ ə m WORD_BOUNDARY k æ n WORD_BOUNDARY b iː WORD_BOUNDARY s l æ ŋ WORD_BOUNDARY b ʌ t WORD_BOUNDARY ɪ t WORD_BOUNDARY k æ n WORD_BOUNDARY ɔ l s oʊ WORD_BOUNDARY b iː WORD_BOUNDARY ʌ WORD_BOUNDARY m ɛ t ə f ɔ ɹ WORD_BOUNDARY ð æ t WORD_BOUNDARY b ɪ k ʌ m z WORD_BOUNDARY p ɑ ɹ t WORD_BOUNDARY ʌ v ð ə WORD_BOUNDARY k ʌ l t̠ʃ ə ɹ WORD_BOUNDARY