If you've been logging incidents of bullying since last October, that sounds serious. If you're able to tell us more, we can comment on the scenarios you give us. Bullying is very personal so it doesn't matter that we don't necessarily deem something to be bullying, the fact is if it makes you feel stressed, humiliated or frightened, then that's bullying because it has affected you negatively.
In law, bullying isn't in itself 'illegal' but that shouldn't stop you from bringing your situation to the attention of an HR person at your place of work, or to a senior person if you don't have HR.
If you're too frightened to confront the person yourself, to advise them of the effect of their behaviour on you personally and your role performance "when you belittle me in team meetings, you humiliate me, so I don't feel I can contribute effectively anymore" then it's acceptable to escalate to HR or manager in an equivalent role (if no HR).
If you feel a Grievance is something you can pull together (a document to advise the nature of your concerns), that could evidence the severity of this person's behaviour, and their effect on you.
If you feel there is discrimination going on (age, sex, race etc), this is harassment rather than just bullying, so it's well worth taking it forward.