Can we understand anything at all, as long as we base our understanding on someone else´s surmise?

Swarn Gill says:
Definitions are different than labels. Words mean what they mean. Some words take on different meanings as they get used commonly so I was simply asking what you meant by ego. I guess I just define the ego differently, or see it playing a different role based on my study of psychology.

Can we analyze this with an impartial outlook?

What is the purpose of definition? Of any definition.

Can we linger on this for a while before giving an answer?
Why du we need definitions? Why are we urged to define things eventually?

Can we learn anything directly through accepting and
taking as good what other people have termed as “real”?

Can we understand anything at all, as long as we base our understanding and rely on someone else´s surmise? – even if this suppositions are called “science”?

Or are we maybe afraid to understand, that is, exposing ourselves to direct and unmediated experience?

How can words and their inherent meaning become other than “common” if we are
to approach them through the filter of yesterday experience…?

Can other people´s “yesterday experience” apply to who we are and what we are being confronted with just now…?

Definitions imply that there is an all-knowing authority. I thus ascribe authority importance, as I am afraid to know, that is, to find out for myself.

So I do wonder:

Can it be so that whatever preconceived definition deprives me of my spontaneous relation to Life and the object of my inquiry?