backtracking

Short definition from Wiktionary

Noun

1. 1
   The act of one who, or that which, backtracks; a retracing of one's steps.
2. 2
   The usage of a runway as a taxiway, especially at private strips and smaller airports.
3. 3
   The act of building all possible solutions to a problem incrementally, abandoning any candidate solution if it cannot lead to a valid solution.

Verb

1. 1
   present participle and gerund of backtrack