I'm going to suggest something important whenever thinking about philosophy in general, but especially when studying epistemology; don't get bogged down in wordage.
Epistemology is about trying to understand knowledge, not splitting hairs about word definitions. & you've hit it on the head, because this issue of words and their meaning is a truly problematic part of philosophy that can create so much confusion between philosophers and between philosophers and students.
What we can do is assume that words mean varying degrees of different things.. to different people.. at different times. There is no objective definition of a word, because we don't learn language by reading the dictionary, we learn it by hearing others speak and use words.
As Wittgenstein would say; Philosophy is an activity of clarification and a critique of language. Words get their meaning by their usage. The meaning of words isn't some objective concrete thing located somewhere apart from us, words are fluid, their meanings change based on what we're trying to communicate with them. Essentially, what this shows us is that even though we often think of our language as being so complex and specific, we actually really just use a few tools(words) to accomplish all kinds of tasks(expressions of meaning).
Wittgenstein’s rejection of general explanations, and definitions
based on sufficient and necessary conditions, is best pronounced.
Instead of these symptoms of the philosopher’s “craving for
generality”, he points to ‘family resemblance’ as the more suitable
analogy for the means of connecting particular uses of the same word.
There is no reason to look, as we have done traditionally—and
dogmatically—for one, essential core in which the meaning of a word is
located and which is, therefore, common to all uses of that word. We
should, instead, travel with the word’s uses through “a complicated
network of similarities overlapping and criss-crossing” (PI 66).
Family resemblance also serves to exhibit the lack of boundaries and
the distance from exactness that characterize different uses of the
same concept. Such boundaries and exactness are the definitive traits
of form—be it Platonic form, Aristotelian form, or the general form of
a proposition adumbrated in the Tractatus. It is from such forms that
applications of concepts can be deduced, but this is precisely what
Wittgenstein now eschews in favor of appeal to similarity of a kind
with family resemblance.