Vicikitsa

Vicikitsa is a Buddhist term that is translated as "doubt" or "indecision". It is defined as being of two minds about the meaning of the Four Noble Truths; it functions as a basis for not becoming involved with unwholesome activities.
Vicikitsa is identified as:

One of the five hindrances that impede meditation
One of the six root unwholesome mental factors within the Mahayana Abhidharma teachings
One of the fourteen unwholesome mental factors within the Theravada Abhidhamma teachings
One of the ten fetters in the Theravada tradition

Explanations

Theravada

Nina van Gorkom explains:
The Atthasālinī defines vicikicchā as follows:

Mahayana

The Abhidharma-samuccaya states:
Herbert Guenther explains:
Alexander Berzin explains:
Chogyam Trungpa states that vicikitsa means "you do not trust any possible alternatives and do not want advice or any way out". This includes doubting the teachings, the teacher, and the dharma, as well as the norms of everyday existence.