The study of word origins is called "etymology," and it's one of my passions - not because it's particularly useful, but rather because it's really interesting. I get to learn things like how one of the words translated "bless" in the New Testament of the Bible is the word "eulogéō," which means "to speak well of, to praise, or to pronounce a benediction upon." This is where we get our word "eulogy," which is a praise or commendation, usually of a deceased person.
So whenever I run across a word that means something other than what I think it should mean, I try to dig into where that word came from, because that usually makes things clearer to me (and easier to remember its actual meaning rather than the meaning I think it should have).
In the Bible specifically, I use the Blue Letter Bible website, which is basically just a database for Strong's Concordance and similar resources, allowing people to look at the word in a specific verse to see what the Greek word is and what it means.
With more common words, I'll use an online etymological dictionary called "Etymonline." This comes in handy when I'm having a conversation with someone and either I use a word they don't know or we disagree on what a word means. That actually happened recently with the word "epoch." It has three different meanings that are all basically the same but slightly different, and I was super confused until I looked up the source of the word.
In case you're curious, it's from Latin in the 1610s, epocha, "point marking the start of a new period in time" (such as the founding of Rome, the birth of Christ, the Hegira), from Medieval Latin epocha, from Greek epokhe "stoppage, fixed point of time." So the use of "epoch" as "a period of time" rather than the beginning or a fixed point within a period, is relatively recent. It's not incorrect, but it's a newer meaning.
To supplement these resources, I also have the Merriam-Webster Dictionary app downloaded to my phone, so that when I encounter a word I do not recognize or that is used in an unfamiliar way, I can look it up. This happens several times a week.
So my question for you, Inklings, is this: What do you do when you encounter a word you don't know, or aren't sure about? What resources do you fall back on?