Jacob's ladder

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Nautical A rope or chain ladder with rigid rungs.
• noun Any of various plants of the genus Polemonium, especially P. caeruleum, having bell-shaped usually blue flowers and alternate, pinnately compound leaves with numerous leaflets.

from The Century Dictionary.

• noun Nautical, a rope ladder with wooden steps or spokes by which to go aloft. Also called jack-ladder.
• noun A common garden-plant of the genus Polemonium, the P. cæruleum, belonging to the natural order Polemoniaceæ: so called from the ladder-like arrangement of its leaves and leaflets.
• noun A toy in which pieces of cardboard, wood, glass, or other material are so connected, one above another, with strings or tapes, that when the highest one is inverted those below it invert themselves in succession.
• noun The carrion-flower, Smilax herbacea.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A flowering plant of the genus Polemonium.
• noun nautical A vertical ladder from the ratline to the upper masts.
• noun A toy consisting of blocks of wood, held together by strings or ribbons, that appear to cascade downward as they flip over.
• noun A pocketknife consisting of two handle segments joined by a pivot, with a blade connected by a second pivot to the end of one handle segment.
• noun mathematics A noncompact surface resembling a ladder made of handlebodies.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun (nautical) a hanging ladder of ropes or chains supporting wooden or metal rungs or steps
• noun pinnate-leaved European perennial having bright blue or white flowers