| ENDEMIC | Widespread within a population |
| GENEPOOL | The total genetic information within a population of animals or plants, usually within a single species (4, 4) |
| GENEFLOW | Result of cross-fertilization within a population |
| FIFTHCOLUMN | Organised group of enemy sympathisers within a population; originally, Franco supporters in Madrid during the Spanish Civil War (5,6) |
| ETHNIC | A population subgroup, within a larger or dominant national group with a common cultural tradition (6) |
| GROUNDSWELL | A big increase in a particular view among a population |
| CENSUS | A periodic official count of a population (6) |
| VOLE | With a population of around 75 million, a field mouse-like animal which is one of Britain's most common mammals; or, in ecarte the winning of all the tricks in one deal (4) |
| PROVINS | In the 13th century, this town was one of the most important towns in France, with a population of 80,000 inhabitants. It was a prosperous wool centre, and its fairs were famous all over Europe. It wa |
| STAPLE | Wire paper-fastener; metal tube inserted into an oboe's reed socket; or, a food forming the dominant part of a population's diet (6) |
| ETHNICAL | Peculiar to a population |
| DIASPORA | Scattering of a population |
| SAMPLE | Subset of a population |
| BIOTA | A population of microorganisms |
| UNSETTLED | Still in doubt, lacking a population (9) |
| HONSHU | Island with a population of about 100 million |
| MODAL | Occurring most frequently in a population |
| SOCIALENGINEERING | The management of a population for desirable change |
| LABOURFORCE | Working members of a population |
| TENACITY | Determination shown by 'X', a population centre (8) |
