Merriam-Webster dictionary says that acceptance is: "the act of accepting something or someone : the fact of being accepted : approval." (source)
When we investigate further and look at accepting, we get a bit further: "able or willing to accept something or someone : inclined to regard something or someone with acceptance rather than with hostility or fear" (source)
This kind of acceptance is also a crucial part of acceptance and commitment therapy, ACT. The very basis is to accept our emotions and struggles. In the case of anxiety, we accept that our hands are shaking, our stomach is in a knot and we're apprehensive.
We do not accept that we are scared cowards (because we are not). We accept that we feel anxious. We are not defined by what we feel, or by our diagnosis.
We do not accept that we will feel like this forever. We accept that right now, we feel anxious.
We do not accept that this is good/bad and must change. We accept that right now we are anxious, and that is all. There is no judgement of it being good, bad, terrible, or having to change.
We do not accept that we are dying and in danger, and whatever else our anxiety tries to tell us. We accept that we have those thoughts.
We do not accept that this is our fate and nothing can be done. We accept that we feel anxious, and based on that acceptance, we can start to think what is a logical course to solve the real problem.
Acceptance vs recognition/acknowledgement
The following example is from the Dutch book Voluit Leven, by Bohlmeijer and Hulsbergen: Let's say that you're lost in the woods. You recognize the situation, but fail to really accept it and everything it means. You'll panic and start running around like crazy... but you won't get far. When you accept the situation (you're lost), you also accept that running around will not help. You need a real plan, such as searching for known landmarks, shouting a bit, maybe climbing a tree to look around.
This is because recognition is narrow, reactive, and solution-oriented. You recognize a danger and react to it. All very fine when it's a real danger, like a car speeding towards you.
Acceptance is acknowledging what is. It's not seeking solutions or assigning blame. It's about taking ownership. Acceptance is wide, proactive and expects no imminent solution.
Examples
Situation: panic attack
Acknowledgement: Help! I'm having a panic attack, so stupid of me, I need to calm down, I cannot do anything else!
Acceptance: I am having a panic attack. It will pass without a trace. I am still in control of my actions and decisions. This is happening to me at this moment, but this does not define me.
Situation: Avoiding a doctor's visit for fear of what they might find.
Acknowledgement: I can't go, it's scary, they will confirm whatever I have and I will become even more anxious, and then I cannot sleep and it's really not good for me. Even though it's good for me, I will not go.
Acceptance: I feel anxious, and my anxiety wants me to avoid this visit. However, I am in control and not my anxiety. Despite the uncomfortable emotions I will go and accept whatever it is they find.
Situation: Avoiding a party because of social anxiety
Acknowledgement: I have social anxiety, I cannot go. I want to see people but I'm scared, no one will want to talk to me and I'll make a fool of myself. To avoid this mess I'll just not go - even though I will miss a chance to have fun, meet new, nice people and listen to great music.
Acceptance: I feel anxious, but I will go anyway. I accept the emotions but I decide to focus on something else. I allow myself the chance to meet new people. Even though there might be awkward moments, I get to listen to music, see people and enjoy the atmosphere.
