A Brønsted or Arrhenius acid usually contains a hydrogen atom bonded to a chemical structure that is still energetically favorable after loss of H+.
ɐ bɹˈɑːnstᵻd ɔːɹ ɚrhˈiːnɪəs ˈæsɪd jˈuːʒuːəli kəntˈeɪnz ɐ hˈaɪdɹədʒən ˈæɾəm bˈɑːndᵻd tʊ ɐ kˈɛmɪkəl stɹˈʌktʃɚ ðæt ɪz stˈɪl ˌɛnɚdʒˈɛɾɪkli fˈeɪvɚɹəbəl ˈæftɚ lˈɔs ʌv ˈeɪtʃ plˈʌs.