causing fear or anxiety by threatening great harm; "a dangerous operation"; "a grave situation"; "a grave illness"; "grievous bodily harm"; "a serious wound"; "a serious turn of events"; "a severe case of pneumonia"; "a life-threatening disease"
involving or causing danger or risk; liable to hurt or harm; "a dangerous criminal"; "a dangerous bridge"; "unemployment reached dangerous proportions"
shut out from view or get in the way so as to hide from sight; "The thick curtain blocked the action on the stage"; "The trees obstruct my view of the mountains"
hinder or prevent the progress or accomplishment of; "His brother blocked him at every turn"