Many seven-syllable words will sound contrived and not be recognizable. This is because, to make them long enough, you will have to add suffixes. Some examples are oxymoronically, and anti-disestablishment.
There are seven syllables in autobiographical
There are 7 syllables in the word "apologetically."
Non-discriminatory has seven syllables.
The word telecommunications has seven syllables. The syllables of the word are tel-e-com-mu-ni-ca-tions.
There are seven syllables. In-di-vis-i-bil-i-ty.
Seven
sev-en
sev-en
There are seven syllables. An-tag-o-nis-tic-al-ly.
There are seven syllables. en-thu-si-as-ti-ca-ly
There are seven syllables in polysyllabilingual. (Pol-y-syl-la-bi-lin-gual)
The word confidentiality has seven syllables. (Con-fi-den-ti-al-i-ty)