SUIT
S-U-B-S-T-I-T-U-T-E :)
s t r a t u s
S-T-E-G-O-S-A-U-R-U-S.
s h u t u p
B e s t q u e s t
s u b a q u a t i c
hiatus
t s u n a m itsunami
s o u g h t
f r u s t r a t e d
r a c i s t s l u r
That is the correct spelling of the word "substituting" (using an alternate).