bighead

noun

Etymology: From big + head.

1. A person with an inflated opinion of themselves; a conceited or arrogant person.

   “He is such a bighead and so lazy that I don't know how far he will go. He can read and write English a little bit and he thinks that is enough for him to know.”

   “'But there are too many egos, way too many. I mean bigheads who are sidetracked by stuff away from football.'”

2. Any of several species of fish having a large head.
3. Any of several animal diseases that cause swelling of the head.