Imposing, a.
1. Laying as a duty; enjoining.
2. Adapted to impress forcibly; impressive; commanding; as, an imposing air; an imposing spectacle. "Large and imposing edifices." Bp. Hobart.
3. Deceiving; deluding; misleading.
1 other Webster entry under this spelling
Imposing, n. (Print.)
The act of imposing the columns of a page, or the pages of a sheet. See Impose, v. t., 4. Imposing stone (Print.), the stone on which the pages or columns of types are imposed or made into forms; - - called also imposing table.
Shades of meaning
Fernald has no entry of its own for imposing; he lists it under awful.
Where he writes about it:
We speak of an exalted station, a grand mountain, an imposing presence, a majestic cathedral, a noble mien, a solemn litany, a stately march, an august assembly, the awful scene of the Judgment Day. — from awful