Anything that doesn’t work properly, or fails to come up to expectations; a dud.
A firework that has been wet and therefore fails to go off correctly.
An obstacle, delay, disadvantage, blow (an adverse event which retards or prevents progress towards a desired outcome)
An offset to the temperature setting of a thermostat to cover a period when more or less heating is required than usual.
A step-like recession in a wall.
The required distance between a structure and a road.