If the holder is affected by Intimidate, it consumes the Adrenaline Orb and its Speed is increased by one stage. It is not consumed if the holder already has +6 Speed stat stages (unless its Ability is Contrary, in which case it won't activate if the holder has -6 Speed stat stages). It is activated even if the holder is not affected by Intimidate due to its Ability (e.g. Hyper Cutter) or Mist, but will not activate if the holder is not affected because it already has -6 Attack stat stages (or +6 in the case of Contrary). It can be obtained as a tier 1 special drop. It is a possible drop from common boss Pokémon.
If multiple Pokémon each holding an Adrenaline Orb are affected by Intimidate, each Pokémon will be affected by Intimidate and consume their Adrenaline Orb before Symbiosis transfers any item (including Adrenaline Orbs).