Underbound

It will be seen that our computation time underbounds his; and that, in fact, we can give a group for which the difference in computation time is arbitrarily large.

Source: wiktionary

The Urbanized Area is often considered the best measure of urban size because it neither "underbounds" the city (by taking just the political city) or "overbounds" it (including peripheral, largely rural areas).

Source: wiktionary

The corporate limits of a city, therefore, offer a political definition that commonly underbounds the geographic extent of the urban area.

Source: wiktionary

When polity underbounds (that is, addresses a subspace within) the space affected by regional policy, the appraisal of development proposals is partial and vital interests go unrepresented.

Source: wiktionary