kerob
כרוב
Etymologically, it is difficult to ascertain a literal meaning for 'kerob'. Clearly, It is the root word of kerobim (aka cherubim), but unlike most other 'im-suffixed words, the root word appears to have fallen put of use, and only the anthropomorphised plural form has a remaining meaning. The usual root form seems to have simply become a singular version of the kerobim.
This is certainly the case in Exodus 25:19 where Moses is instructed to “make a kerob”, or presumably a graphical depiction of one. This same usage appears to be the case in nearly every instance of 'kerob'.1)
A notable exceptions occurs in Psalms 18:10, where David describes his hero Ihoh, “riding on Kerob flying on the wings of Roeh”.2)
Note that this song is a narrative description of events that David witnessed. David describes a physical object that could fly, and that Ihoh rode when he came to David's rescue.
The prophet Ezekiel tells a similar narrative. He was transported by air and described the object as a 'kerob' which lifted Ihoh up into the sky. 3)
LexID 3742