gurei-fokkusu means "Gray Fox" in English.
It's a katakanization, a loan-word.

gurei-fokkusu is normally written with katakana, as グレイフォックス.
gurei-fokkusu written with hiragana is ぐれいふぉっくす.
gurei-fokkusu does not have kanji.
Romaji gu re i fo kku su
Meaning Gray Fox

Orthography Notes

  • フォ is a compound kana representing a single syllable with multiple characters.
  • ック contains a small tsu which makes the consonant of the syllable longer.