Brother in law

Question

I call my sister's husband my brother in law and I also call my husband's brother my brother in law.

In 1787 my DH 5 X grt grandfather renounced his claim for compensation for damages to his property in the Mohawk valley-burnt to the ground- in 1778-he was a British loyalist, which is not that important.

The reason he renounced the claim was because his brother in law now had possession of the land.

Was his brother in law, his sister's husband or his wife's brother? Has this word use changed over time? Or is used differently in different countries?

Comments

Just to muddy the waters even more - - one's step-sibling, or step-parent was also an "in law", because they were related BY LAW, not by blood.

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Yes, that was the common understanding of the term at that time.  "In-law" generally meant what we mean today by "step."

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Thanks, on Sept 1 1787 he renounced his claim, records for a judgement exist.

This is what the records say: Dated 9/1/1787 recorded 10/6/1787, the Inferior Court of Common Pleas, the lands of William McClellan be seized for a Judgement to be paid to the estate of Robert Campbell, to James McDermot of Cherry Valley,

Robert Campbell was the son of the people that William originally bought the land from in 1773. I haven't looked for a death for him, so for now I assume he was dead.

Does this mean James McDermot is the brother in law or step brother? And he had somehow claimed the land from the estate?

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Who is the other related person?

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Sorry, the 5 x grt grandfather is William McClellan. I'm in the process of adding more details to his biography and relevant sources. I hoped that McDermot was William's wife's brother as that would provide a LNAB for her. 

If he is a 'step brother' in today's meaning or his sister's husband both of which are probably very unlikely based on what else we know about him it doesn't help me at all, but after 7 years of trying to find his wife's LNAB I'm not holding my breath

https://www.wikitree.com/wiki/McClellan-277