sometimes i cant say a specific word. my brain wont do it

sometimes i cant say a specific word. my brain wont do it Depends on my mental status in that situation, but sometimes i got anxious and for some reason i can't say a particular world. For example "spiderman". if i want to say spiderman with that block, my lips are frozen. it's like someone is covering my mouth or it's glued and i cant say that word. The same as the sleep paralysis where you want to move so badly but ur body wont. I experience the same thing. Or i try to force myself to say that word, where i really need to put a lot of effort and energy and weird facial expression like im moving a heavy object, or i cant. But it's killing me because if i try to say that word, i look weird lol The solution ive found is to find synonimous. same example with "spiderman", i want to say "do you see the new spiderman?" instead i cannot say spiderman i say "do you see.. the new.. i mean, morales. yes, the new superhero, webshooter.." I remember that i was with a friend and wanted to say a word and i felt like sleep paralysis where i cannot say that word. While in my mind i keep trying to find a way to say it, he was keep talking to me about anything else, and i could talk normally to him. It's like, my mind blocked that particular word ​ Is this stuttering or something else?