  Hidden theories coupled to the SM may provide emergent axions, that are
composites/bound-states of the hidden fields. This is motivated by paradigms
emerging from the AdS/CFT correspondence but it is a more general phenomenon.
We explore the general setup and find that UV-sourced interactions of instanton
densities give rise to emergent axions in the IR. We study the general
properties of such axions and argue that they are generically different from
both fundamental and composite axions that have been studied so far.
