īr
The modifier īr refers to the back of something. This is the same root as sīra. So, rā NP īr is to the back of NP or to behind NP and rū NP īr is from the back of NP or from behind NP.
rājīr
rājīr is rā NP īr without a specified location, and so means ‘to the back’.
rūjīr
Likewise rūjīr is rū NP īr without a specified location, and so means ‘from the back’ or ‘from behind’.