I still hear that expression pretty often. Especially about now. To me it's pretty much Jan. - Feb. when some of the coldest and cruelest winter settles in. Single digits last night and about 13 deg. this afternoon. Seeing very few birds & hearing none. Out in the woods there's that dead, muffled, silence that comes with frigid temps and a foot and a half of snow. So silent that it's downright eerie. Almost no deer movement and hard to even find tracks. Although Sunday afternoon I was shoveling the end of the driveway after the plow run filled it in and caught 3 deer crossing the road about 75 yds. away. First deer I've seen in a couple weeks. The deer are pretty much "yarding up" now, which means they gather in a sheltered place like under some large pines with low branches where they are out of the wind and won't get snowed on. Then they pretty much lay low and don't move much so they can conserve precious calories. They'll move when they get hungry enough but otherwise move very little. So to both me and the local deer herd this would be "dead of winter".