The word "Gravius" is spelled with a combination of letters that may seem odd at first glance but can be explained using the International Phonetic Alphabet (IPA). The first syllable "gra" is pronounced as /ɡrə/, with the "a" sound like the one in "calf". The second syllable "vi" is pronounced as /vɪ/, with the "i" sound like the one in "sit". Finally, the ending "-us" is pronounced as /əs/, with the "u" sound like the one in "but". Together, these sounds create the unique spelling and pronunciation of the word "Gravius".