Definition of "suburban"

Suburban villas, highway-ſide retreats, / That dread th' encroachment of our growing ſtreets, / Tight boxes, neatly ſaſh'd, and in a blaze / With all a July ſun's collected rays, / Delight the citizen, who gaſping there, / Breathes clouds of duſt and calls it country air.

1782, William Cowper, “Retirement”, in Poems, London: […] J[oseph] Johnson, […], page 282

They form part of the vast electrification and reconstruction schemes which have been in hand for a number of years at Liverpool Street, and in suburban Essex, and include the rearrangement of tracks, of which the Ilford flyover forms part; the modern signal boxes, now needed only at key points; the electric control or sub-stations; and a large electric car shed.

1951 January, R. A. H. Weight, “A Railway Recorder in Essex and Hertfordshire”, in Railway Magazine, page 44