The word "Greyfalcon" is spelled with a combination of two words, grey and falcon. The IPA phonetic transcription of "Greyfalcon" is /ɡreɪˈfælkən/. The first syllable "gre" is pronounced with a long A sound, followed by the diphthong "ey". The second part "Falcon" is pronounced with a short A sound and ends with the nasal consonant "n". Thus, the correct spelling of this word depends on recognizing the combination of two words that create this hybrid term.