swelled head, to have a

have a swelled head

To be conceited, arrogant, or self-aggrandizing. Cheryl has such a big head on her, all she ever talks about is herself. Janice has had a bit of a big head ever since she got that promotion.
See also: have, head, swell
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

swelled head, to have a

To be conceited. The image conveyed is that of having one’s self-importance augment one’s head size. The term dates from the nineteenth century. J. J. Cooper used it with appropriate disgust (Simon Suggs’ Adventures, 1845): “They’re all a pack of d——d swell-heads.”
See also: have, swell, to
The Dictionary of Clichés by Christine Ammer Copyright © 2013 by Christine Ammer
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