A race of giants that appear in the Bible. The Bible states that they are descendants of Nephilim.
However, since these were supposedly all annihilated during Noah's flood, and then recorded later, it has become one of the major biblical difficulties. The Bible does not clearly state their origin or characteristics. The most reasonable conclusion that can be inferred from the existing records is that the term Nephilim was used as a synonym for giants in the past, and exceptionally tall people were idiomatically referred to as 'descendants of Nephilim.'
In particular, the first record of these Anakim appears in the testimony of the Canaanite spies. Considering the fear they would have felt when they encountered large and formidable foreign people after having lived as slaves in Egypt and then coming to Canaan to spy, such an expression can be somewhat understood.
Subsequent records in the Bible do not provide specific grounds or background for the Anakim, but mostly use them as a 'synonym for giants.'