Not fitted, provided, or strengthened with iron; (of a prisoner, etc.) unfettered, unshackled; (of a roadbed) not laid with iron rails.

Not paved. Also figurative.

Originally U.S. Applied to a road or causeway constructed of trunks of trees laid together transversely across a swamp or miry ground; hence, to…

Of a road: made or repaired according to McAdam's method; surfaced with tarmacadam.

Of a road: surfaced with road metal.

Of a road: not macadamized; (hence) bumpy, difficult to negotiate.

Not paved with flagstones.

Of a road: not surfaced with road metal. Cf. metalled, adj. 2.

Formed as a corduroy road.

Having a soft and clinging texture; said esp. of edible things which are consequently unpleasant to the palate; also of the surface of a road…

Of clay, gravel, etc.: having the particles or grains bound by water; esp. designating roads (typically of crushed stone or macadam) compacted by…

Designating a road, car park, etc., surfaced with a hard material such as concrete or asphalt. Cf. blacktop, n.