acyoominate is what the ear actually delivers
long-uThe second syllable of acuminate says kyoo, and that y sound has no letter of its own in the spelling.
heard asacyoominate
spelledacuminate
saiduh-KYOO-min-ut
The word is spelled acuminate.
Two letters against four. There is no rule that would let you work back from the sound to the spelling here, only the fact that this word came from Latin and Latin never wrote the y.
Filed alongside
acumanate acuminnate accuminate acumminate acumunate acyouminate
All of them are filed together. All 7 spellings of acuminate.