Some of us and English learners say 'He thinks he is only clever in our class' to tell about who always thinks that they are intelligent than they are. Using 'clever' word is also correct but there is a perfect word which is suitable and gives correct meaning.
Part of speech: Adjective
Meaning: Thinking you are important and intelligent than you are.
Usage and Examples of Big-headed:
My neighbour is a big-headed. There is no point in caring his words.
Here I say my neighbour always thinks he is only intelligent than others.
Rajini: Ragini is big-headed. That is why she did not spend more time with you.
Rajini says that Ragini thinks she is important than all.
Article by Padmasri