Rickety means shaky and likely to collapse. A chair you test with one hand before sitting on it.
The word suits furniture, ladders, bridges and staircases, and it always implies age and neglect rather than bad design. It carries a comic edge, since rickety things wobble rather than fall. Figuratively it describes anything unsound, so a rickety argument or a rickety coalition is one that will not survive pressure. The word comes from rickets, the bone disease caused by a lack of vitamin D.
1adjectivericketyUnsteady and likely to break or collapse.
“They climbed a rickety wooden staircase.”
From dialectal ricket + -y, and/or ricket + -y. Alternatively, and perhaps less likely, from rickets + -y.
Etymology from Wiktionary, CC BY-SA