| double(adjective, adverb, part, like, big) |
| dual(adjective, part, like, double, identical) |
| paired(adjective, like, double, identical, second) |
| binary(adjective, part, like, double, identical) |
| duplex(adjective, part, spare, equal, double) |
| duplicate(adjective, part, like, spare, double) |
| twin(adjective, like, spare, duplicate, double) |
| doubled(adjective, duplication) |
| second(adjective, like, identical, duplication, matching) |
| duple(adjective, part, spare, equal, double) |
| treble |
| twice(adjective, adverb, double, duplication, second) |
| bifold(adjective, like, double, identical, duplication) |
| biform(adjective, part, double, duplication) |
| threefold |
| two-fold |
| as much again(expression, adjective, idiom, duplication, second) |
| bivalent |
| doubly |
| duplicated(adjective, second, dual, twice as much) |