The word "Fostress" is spelled with the IPA phonetic transcription /ˈfɒstrəs/. This word is derived from the word "foster", which means to nurture and care for someone as a parent would. The suffix "-ess" is added to indicate a female fulfilling this role. Therefore, a "Fostress" can be seen as a female guardian who is fostering a child. The spelling of this word follows the standard English spelling rules for prefixes and suffixes.