1.
If you miss out on something that would be enjoyable or useful to you, you are not involved in it or do not take part in it.
We’re missing out on a tremendous opportunity...
Well, I’m glad you could make it. I didn’t want you to miss out.
= lose out
PHRASAL VERB : V P on n , V P
2.
If you miss out something or someone, you fail to include them. ( BRIT; in AM, use leave out )
There should be an apostrophe here, and look, you’ve missed out the word ‘men’ altogether!...
What about Sally? You’ve missed her out.
= leave out
PHRASAL VERB : V P n (not pron) , V n P