What is the meaning of ひ?
The hiragana syllable ひ (hi). Its equivalent in katakana is ヒ (hi). It is the twenty-seventh syllable in the gojūon order; its position is は行い段 (ha-gyō i-dan, “row ha, section i”).
indeed, truly
A shriek, as when recoiling in fear or disgust.
Source: wiktionary.org