ladder

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

• noun An often portable structure consisting of two long sides crossed by parallel rungs, used to climb up and down.
• noun Something that resembles this device, especially a run in a stocking.
• noun A means of moving higher or lower, as in a hierarchy.
• noun A series of ranked stages or levels.
• noun A fish ladder.
• noun An athletic workout in which one does progressively longer intervals followed by progressively shorter intervals.
• noun One of the intervals in such a workout.
• intransitive verb To run, as a stocking does.

from The Century Dictionary.

• noun A series of buckets for dredging and filling which are carried up and down an incline; a bucket-conveyer.
• noun In railroads, a track which connects by switches the ends of a series of parallel tracks and is used in sorting cars in a drill-yard. See drill-yard.
• noun A frame of wood, metal, or rope, usually portable, and consisting essentially of two side-pieces connected at suitable distances by cross-pieces, generally in the form of rounds or rungs, forming steps by which, when the frame is properly set, a person may ascend a height.
• noun Figuratively, any means of ascending; a means of rising to eminence.
• noun In logic, a figure illustrating the theory of the old logic concerning the relations of genera, differences, and species
• noun Nautical See Jacob's-ladder, 1.

from the GNU version of the Collaborative International Dictionary of English.

• noun A frame usually portable, of wood, metal, or rope, for ascent and descent, consisting of two side pieces to which are fastened cross strips or rounds forming steps.
• noun That which resembles a ladder in form or use
• noun See under Fish.
• noun (Zoöl.) an American leaf beetle (Chrysomela scalaris). The elytra are silvery white, striped and spotted with green; the under wings are rose-colored. It feeds upon the linden tree.
• noun an iron rail at the side of a vertical fixed ladder, to grasp with the hand in climbing.
• noun (Zoöl.) a spiral marine shell of the genus Scalaria. See Scalaria.

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

• noun A frame usually portable, of wood, metal, or rope, for ascent and descent, consisting of two side pieces to which are fastened cross strips or rounds forming steps.
• noun That which resembles a ladder in form or use; hence, that by means of which one attains to eminence, e.g. the corporate ladder.
• noun chiefly UK Length of unravelled fabric in a knitted garment, especially in nylon stockings.
• noun In the game of go, a sequence of moves following a zigzag pattern and ultimately leading to the capture of the attacked stones.
• verb firefighting To ascend a building or wall using a ladder.
• verb of a knitted garment To develop a ladder as a result of a broken thread.

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

• verb come unraveled or undone as if by snagging
• noun ascending stages by which somebody or something can progress
• noun steps consisting of two parallel members connected by rungs; for climbing up or down
• noun a row of unravelled stitches