In salvage vs. selvage, I was reminded of using a sewing machine. When I was first married I asked my wife to mend
a shirt. She told me to learn to use the sewing machine. So I did. Twenty years later she was asking me to show her which way the bobbin went into the shuttle. With the thread
exiting at an obtuse angle, naturally.
Obtuse reminded me of "obtund" = relieve "acute" pain.

Source: The Collins English Dictionary © 2000 HarperCollins Publishers:

obtund [ɒb'tʌnd]
verb [transitive] (rare)
to deaden or dull
[ETYMOLOGY: 14th Century: from Latin obtundere to beat against, from ob- against + tundere to belabour]
ob'tundent adjective, no