This term is not at all infrequently seen in GD. What does it mean?
Here’s a decent definition of it: link.
The website it is on is a good one to bookmark, as well:
http://www.fallacyfiles.org/
Incidentally, a strawman is another term for a scarecrow, one of those things you used to see in fields which were supposed to scare birds away from the crops. They are now quite rare. They consisted of clothes stuffed with straw on a cross of sticks which were supposedly able to fool birds into thinking that they were people. I suspect that the only time most people these days ever see one, even in movies or TV, is the Scarecrow in the movie of The Wizard of Oz. The point of the metaphor is that smashing a scarecrow is easy, unlike a real person.
Carl Sagan in The Demon-Haunted World {an indispensable read in the fight against ignorance} gives a succinct and excellent definition: “…caricaturing a position to make it easier to attack {eg Scientists suppose that living things simply fell together by chance - a formulation that wilfully ignores the central Darwinian insight, that Nature ratchets up by saving what works and discarding what doesn’t.”