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

But you were on the right track, Doc. L. obtundo, obtundere, obtudi, obtusum (also obtunsum) 'to beat (on), thump; to stun, deafen, annoy, importune'. In traditional Latin grammar, verbs are given in four forms in the dictionary from which the rest of the verbal paradigm (or conjugation) should be recreatable: first person singular present indicative, infinitive, first person singular present perfect, and finally the neuter past particple. In the example above: 'I thump', 'to thump', 'I have thumped', 'thumped'. Same idea worked for the nominal paradigm (or declension): cite nominative singular and genitive singular, and the rest follow. (Sometimes there are exceptions, and those would be listed, too, after the four (or two) paradigmatic examples.

You incidentally reminded me of the buzzword "paradigm shift"/.