Irrealizable and Off-the-wall

Off-the-wall and irrealizable are semantically related. In some cases you can use "Off-the-wall" instead an adjective "Irrealizable".

Off-the-wall adjective - Different from the ordinary in a way that causes curiosity or suspicion.

Irrealizable and off-the-wall are semantically related. Sometimes you can use "Irrealizable" instead an adjective phrase "Off-the-wall".