The spelling of the word "Gunstome" can be explained using the International Phonetic Alphabet (IPA) as follows: /ˈɡʌnstəʊm/. The first syllable "gun" is pronounced with the short u sound /ʌ/, followed by the sound /s/ in the middle syllable "stom". The final syllable "-e" is pronounced with a silent /ə/ sound. Therefore, the correct spelling of this word is "gunstock", referring to the wooden part of a gun that rests against the shoulder while shooting.