Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I must eat. devour you must eat. devour she must eat. devour we must eat. devour you must eat. devour they must eat. devour
V-ing form
I must be eat. devouring you must be eat. devouring she must be eat. devouring we must be eat. devouring you must be eat. devouring they must be eat. devouring
Perfect
I must have eat. devoured you must have eat. devoured she must have eat. devoured we must have eat. devoured you must have eat. devoured they must have eat. devoured
V-ing perfect
I must have been eat. devouring you must have been eat. devouring she must have been eat. devouring we must have been eat. devouring you must have been eat. devouring they must have been eat. devouring
Negation
Simple form
I must not eat. devour you must not eat. devour she must not eat. devour we must not eat. devour you must not eat. devour they must not eat. devour
V-ing form
I must not be eat. devouring you must not be eat. devouring she must not be eat. devouring we must not be eat. devouring you must not be eat. devouring they must not be eat. devouring
Perfect
I must not have eat. devoured you must not have eat. devoured she must not have eat. devoured we must not have eat. devoured you must not have eat. devoured they must not have eat. devoured
V-ing perfect
I must not have been eat. devouring you must not have been eat. devouring she must not have been eat. devouring we must not have been eat. devouring you must not have been eat. devouring they must not have been eat. devouring
Interrogative form
Simple form
must I eat. devour? must you eat. devour? must she eat. devour? must we eat. devour? must you eat. devour? must they eat. devour?
V-ing form
must I be eat. devouring? must you be eat. devouring? must she be eat. devouring? must we be eat. devouring? must you be eat. devouring? must they be eat. devouring?
Perfect
must I have eat. devoured? must you have eat. devoured? must she have eat. devoured? must we have eat. devoured? must you have eat. devoured? must they have eat. devoured?
V-ing perfect
must I have been eat. devouring? must you have been eat. devouring? must she have been eat. devouring? must we have been eat. devouring? must you have been eat. devouring? must they have been eat. devouring?
Interro-negative form
Simple form
must I not eat. devour? must you not eat. devour? must she not eat. devour? must we not eat. devour? must you not eat. devour? must they not eat. devour?
V-ing form
must I not be eat. devouring? must you not be eat. devouring? must she not be eat. devouring? must we not be eat. devouring? must you not be eat. devouring? must they not be eat. devouring?
Perfect
must I not have eat. devoured? must you not have eat. devoured? must she not have eat. devoured? must we not have eat. devoured? must you not have eat. devoured? must they not have eat. devoured?
V-ing perfect
must I not have been eat. devouring? must you not have been eat. devouring? must she not have been eat. devouring? must we not have been eat. devouring? must you not have been eat. devouring? must they not have been eat. devouring?