Cannula is the
Latin diminutive of the
Latin "
canna", or "
cane".
Cane is a plant or family of plants, much like a
reed or
bamboo; in
English "
a cane" is the
stem of a
cane plant. "A
cane" has properties: It is long and narrow and hollow in the middle. And that's where we start from.
There is a
cane which is a
walking stick, not often made of
cane, but "a
cane" is good for more than just to lean on. "
Canna" is a unit of
Italian distance, and a
canon is a
ruler or measuring rod: In parallel there is a "
rule" that you follow, which is the same word as a
rule for measuring. A
canon is a
rule,
axiom, or law; it is the
rule (of conduct and worship) for a
monastery, hence the book containing that rule;
The Canon is the official list of whatever it is you're discussing, and a
canon is a
prebendary, an
ecclesiastical figure who
officiates in return for a
benefice1.
The
Spanish cañon or
canyon opens out from the
Spanish caña, a
cane or
reed, and it is hollow inside. The
cannula the good
doctor inserts into your
vein is hollow too, but a
cannel2 --
channel, or
canal seems to have been open on top to begin with and only closed up when it became a
conduit: Apparently it's not related. A
cannon that thunders (formerly "
canon") is long and hollow inside, and it is related, while "
cant" is the unrelated "bent", but it does by chance happen to be as long and hollow as the rest. A
canon loses its length in the
OED's sense 14, where it becomes "a metal loop or 'ear' at the top of a
bell, by which it is hung", and gains it back again in the
cannular (but not
canicular!) ornamental rolls on the ends of your
breeches; these rolls are called
canions.
Yes, and a
candy cane comes from
sugar cane in the factory, and from
cane in the
OED as well.
"
Canoe" is from the
New World and unrelated. A
Menckenian "
cannaille",
a pack of dogs and by extension a
rabble, is from the
Latin "
canis" or "dog", and is unrelated. The
Gaelic "
cannach" is
cotton-grass, and is from something spelled "
canna" by somebody, somewhere. It looks interesting, but the trail is cold . . . The "ch" is something a bit like the throat-clearing "ch" of modern
Hebrew. I'm not so sure about
Lucas Cranach. I think he's unrelated, too.
1 We'd all do well to have a
benefice.
2 A
cannel is also a
candle with an
elided 'd'.