Pressure

Increases the PP cost of moves targetting the Pokémon by one.

Full effect

Moves targetting this Pokémon use one extra PP. This ability stacks if multiple targets have it. This ability still affects moves that fail or miss. This ability does not affect ally moves that target either the entire field or just its side, nor this Pokémon's self-targetted moves; it does, however, affect single-targetted ally moves aimed at this Pokémon, ally moves that target all other Pokémon, and opponents' moves that target the entire field. If this ability raises a move's PP cost above its remaining PP, it will use all remaining PP. When this Pokémon enters battle, all participating trainers are notified that it has this ability. Overworld: If the lead Pokémon has this ability, higher-levelled Pokémon have their encounter rate increased.

In game description

Puts other Pokémon under pressure, causing them to expend more PP to use their moves.

Pokemon with Pressure

Using Pressure in Cobblemon

Abilities are passive and always active, so Pressure costs you nothing to run. If it is marked hidden on a species above, expect it to be harder to obtain: servers differ in whether hidden abilities come from breeding, an Ability Patch, or events.

See the Pokedex for which abilities each species can have, and IVs, EVs and breeding for how to actually pass one down.