emarginute puts a u in the ending
schwaEmarginate has one stressed syllable, MAR, and four unstressed ones. Those four vowels are all reduced in speech and all guessable in writing.
heard asemarginute
spelledemarginate
saidee-MAR-jin-ut
The ending is -ate: emarginate.
By the time the word reaches its last syllable there is no stress left to give the vowel a shape, so it comes out somewhere between an a and a u. Every adjective of this family takes -ate.
Nearby in the file
emargenate emarginat emerginate emarrginate emarjinate emarginnate
The rest are on the word page. All 11 spellings of emarginate.