He is acting too big for his boots lately.
too big for one's boots
idiomFar less important or capable than one thinks or claims oneself to be.
The new manager started acting too big for his boots, so the team stopped listening to his advice.
Despite his lack of experience, he became too big for his boots and began lecturing the senior partners on how to run the firm.
- 01
abound in one's own sense
To follow one’s own inclinations and opinions.
- 02
ace up one's sleeve
A surprise advantage of which others are not aware.
- 03
act one's age
To behave in a manner appropriate to one's age.
- 04
act one's age, not one's shoe size
Synonym of act one's age (“to behave in a mature manner; to avoid being childish”).
- 05
afraid of one's own shadow
Exceptionally timid.
- 06
air one's dirty laundry in public
To reveal one's sordid secrets to the public.
- 07
air one's dirty linen in public
Synonym of air one's dirty laundry in public.
- 08
albatross around one's neck
A characteristic, possession, associate, or previous deed that hinders one's ability to succeed.