Dry thrust usually means the non-augumented thrust i.e. thrust without the use of afterburners or liquid injection. The maximum thrust produced by jet engines w/o afterburner is sometimes called military thrust.
The thrust of a jet eingine can be increased by using methods like water(+methonol) injection (mostly in older turbojet engines) or by using afterburners (or reheat). In such cases, the (higher) thrust produced is called wet thrust.