Pedido - order/ordered

I was halfway through a sentence on the phone today when I realised that I didn't know the word for an order. I knew the verb 'to order' ('pedir') and hence how to say 'I have ordered' ('he pedido') but the noun escaped me. It turns out, after a quick check on Word Reference, that it is 'pedido' - a word I could perhaps have guessed at but didn't. I am not sure if there is any advice to avoid that situation when it happens, although usually it will be possible to think of another way to say something. When asking a more complicated question it is often worth mentally rehearsing it in your head, but it is impossible to do this in a conversation if you want to sound fluent.