Machete

A machete was a large knife.

Sontarans sometimes used them. (TV: The Sontaran Experiment).

The Tenth Doctor and Rose Tyler used machetes to cut foliage while searching for the Dramos. (COMIC: Blood and Tears)

Chris Cwej used one to cut open coconuts when he and the Seventh Doctor were stranded on an island. (PROSE: No Room)