UPDATED ARTICLE

Both “throughly” and “thoroughly” appear in the Bible.

The words cannot be synonyms, because if they just mean the same thing, then why use two different “spellings”? But clearly there is some distinction in meaning. Following a simple process, we find distinction of meanings of words by a two step method:
1. Examining all the places each word is printed using a standardised, pure edition.
2. Then examining dictionaries/records.

In fact, a full examination of this topic needs to be made, because when I wrote a book mentioning this in passing, I didn’t really look into it.

Looking into it tentatively, from the Scripture it could be suggested that THROUGHLY means fully/completely, and that THOROUGHLY means to have gone through, like as a process that penetrates or accomplishes an exacting going right through. However, I think a fuller examination has to be made of the topic.

Also, for assistance, here is the information from the Oxford English Dictionary.

OED -> Throughly. 1. Fully; completely; perfectly. 2. Through the whole thickness, substance or extant; through, throughout, all through, quite through. And a subcategory meaning to that, Through, from beginning to end; for the whole length or time; all through.

OED -> Thoroughly. 1. In a way that penetrates or goes through; right through, quite through. 2. In thorough manner of degree; in every part of detail; in all respects; with nothing left undone; fully, completely wholly, entirely, perfectly.

It used to be said by some KJBO advocates many years ago that “throughly” meant “fully through the inside as well as the outside” while “thoroughly” just meant on the outside. So this implied that the meaning dichotomy was on whether the description was to do with the inside of something. I expect that those old definitions were not based upon a full examination nor were rigorously correct. Moreover, some people have looked into this area since to study further the distinctions.

Someone could just take the first definitions from both entries of the words from the OED, and this already shows, by the differences between them, that these are two separate words with separate meanings.

Simplistic definitions as given by others abound, and the internet is full of all kinds of possibilities of meaning. Rather than confuse the issue, I will make a more comprehensive study, because it is evident that

There are people who try and say that these two words mean the same thing. They do this because they are taking simplistic looks at dictionaries and also trying to make out that 1611 spelling is authoritative over current editions.

While it is true there are very close similarities in both spelling and meaning, they are not the same thing. I also think that definitions given in the past, when the issue had not yet been looked at properly, could give rise to people saying that such things are wrong or unclear, leading some to claim that there is no difference meaning.

Just because spellings in old KJB editions have varied, this does not mean that spelling doesn’t matter or that the words are identical after all. Lack of standardised English orthography, typographical errors, etc. are all possible factors.

We know that the way it is now in our current edition is correct, and that typography and orthography were not always so precise, when we begin from 1611 or from Tyndale.

Thus, the need to better understand and define words or differences, where study needs to be done. So far, in my preparation for a more concerted examination, it is obvious that there is a distinction between “throughly” and “thoroughly”, that they are not just the same thing or a meaningless spelling variation of the same word.