1.
If someone or something is left off a list, they are not included on that list.
She has been deliberately left off the guest list...
The judge left Walsh’s name off the list of those he wanted arrested.
PHRASAL VERB: be V-ed P n, V n P n, also V n P
2.
If someone leaves off doing something, they stop doing it.
We all left off eating and stood about with bowed heads...
Some of the patients left off treatment.
= stop
PHRASAL VERB: V P -ing, V P n (not pron)