Dimension

"Time, like space, although a dimension of itself, also has dimensions of its own."

- Vicki Pallister

The universe had 11 dimensions (NA: Parasite), space and time were two of these dimensions and were related. The Doctor has stated that the fourth dimension was time. (DW: An Unearthly Child) Hyperspace was another dimension. (DW: The Stones of Blood)

A TARDIS' interior existed as a separate dimension. (DW: The Hand of Fear)

A location of space known as the Arc of Infinity was known as an ancient curve between dimensions. (DW: Arc of Infinity)

N-Forms were constructs created by the Patrexes that were able to cross the dimensions, and existed in pocket dimensions of their own. (NA: Damaged Goods)

Other dimensions
According to Fenric, the Doctor trapped him in the Shadow Dimensions for 17 centuries. (DW: The Curse of Fenric)

The Doctor claimed a craft found in Lake Vortigern was from another dimension or a parallel universe. (DW: Battlefield)

Anti-Time was a dimension created by the use of the Oubliette of Eternity; it was inhabited by the Neverpeople. (BFA: Neverland)

Jason Kane spent several years in a hell dimension that was predominately rock, where tunnelling craft tunnelled their way between habitable areas. (BFBS: The Infernal Nexus)

Species from different dimensions

 * Neutron eaters (BBCR: Lost Souls)
 * Spillagers (BFA: Winter for the Adept)
 * Daleks from another dimension (BFDE: Project Infinity)