Aikido is more of a concept, rather than a noun or adjective...
But if you're speaking of certain movements or martial arts, I guess you could say anything that is flowing, requires none of your own energy, and doesn't harm your opponent is Aikido-like.
I have to say the concept of harming can be tricky, very subjective to the situation or the opponent that is involved. Aiki has a broad array of meanings to many people.
I would say more or less, subduing the opponent is more the way I would describe it. Using flow and the opponents energy to redirect and allow for some sort of lock/choke to stop the aggression. Some Aiki techniques will cause some degree of pain.