Correct spelling

seizure

Correct spelling, explanation: seizure is the correct form because the noun comes from the verb to seize, to which a noun suffix is added. The word derives from Old French seisire, hence the English spelling seizure, not siezure.

Definition of seizure:
noun, an act of holding a possession by force or by law; also: an attack (for example of illness), this meaning occurred in the 18th century.
The seizure of the entrance is displayed on the monitor.
The patient has a history of seizures.
I entered the room without knocking and my husband had a seizure.


Incorrect spelling

siezure

Incorrect spelling, explanation: although pronunciation may be misleading, siezure is an incorrect form. The correct form is seizure, from the verb seize, which originates in French seisire. Therefore seizure is the correct spelling.