Is “Backtracking” a Scrabble word?

1.To retrace one's steps.

“I dropped my sunglasses and had to backtrack to find them.”

2.To repeat or review work already done.

“If we backtrack through this problem, maybe we can figure out where we went wrong.”

3.To taxi down an active runway in the opposite direction to that being used for takeoff.

“Speedbird One: enter and backtrack Runway 27 Left.”

1.(countable, uncountable) The act of one who, or that which, backtracks; a retracing of one's steps.

2.The usage of a runway as a taxiway, especially at private strips and smaller airports.

3.The act of building all possible solutions to a problem incrementally, abandoning any candidate solution if it cannot lead to a valid solution.