UAP
noun
Elementary
1
Initialism of unidentified anomalous phenomenon. The umbrella category for all environments.
2
Initialism of unidentified aerial phenomenon = initialism of unexplained aerial phenomenon.
3
Initialism of unlicensed assistive personnel (plural) or unlicensed assistive personnel member (singular): workers who are trained to assist with nursing tasks but are not trained or licensed to do everything else that a nurse can do.