Azaborane usually refers a borane cluster where BH vertices are replaced by N or NR (R stands typically for H or organic substituent).
Like many of the related boranes, these clusters are polyhedra and can be classified as closo-, nido-, arachno-, etc..
Within the context of Wade's rules, NR is a 4-electron vertex, and N is a 3-electron vertex.
Prominent examples are the charge-neutral nido-NB10H13 (i.e. (NH)(BH)10) and closo-NB11H12 (i.e.
[2] Azaboranes can also refer to simpler compounds including iminoboranes (RB=NR', where R and R' stand typically for H or organic substituent) and borazines.