In philosophy, 'alief' refers to an automatic or habitual belief-like attitude that is less reasoned than a belief. Generally, we only bother to identify an alief when they conflict with a stated belief, but in fact many of our beliefs are aliefs that we haven't had contested yet.
The classic examples are cases of mild phobias. The first to use this term was philosopher Tamar Gendler in 2008, who used the example of the Grand Canyon Skywalk, a glass walkway that extends out over the depths of the canyon. Presumably, a person willing to walk out onto this skywalk has a fairly strong, reasoned belief that they are not about to fall to their death, but they may still have a strong feeling of danger -- they believe that they are safe, but alieve that they are in danger. Other examples include firmly believing that a snake is not venomous, but still being hesitant to pick it up, or feeling reluctant to eat a bit of fudge that has been shaped to look like cat poop.
Aliefs are far from useless. We all know that actors are acting and that the characters in books are imaginary, but we can still alieve that the things happening to them matter, and thus we have an emotional response to them. Perhaps more importantly, feeling that a snake is a dangerous thing, and therefore thinking twice before picking it up, may well save our lives in some instances. While it is good to know that some snakes are safe, it is also good to have an automatic, veto-proof feeling that this is a dangerous situation.
Aiefs can also be troublesome, however. Many people have reasoned beliefs about the unlikelihood of dying in an airplane crash, the evils of racism, or the importance of designated drivers, only to have their aliefs turn traitor on them. It is surprisingly common for people to behave in ways that go against their stated beliefs, and while in many cases we are quite right to suspect intentional deception and hypocrisy, it is also important to remember that some beliefs are firmly held in the face of strong aliefs, and the challenge is not an increase in integrity, but an increase of self-awareness.