too big for one's breeches

Từ điển WordNet v3.1 - WordNet Dictionary

adjective

(used colloquially) overly conceited or arrogant
- "a snotty little scion of a degenerate family"-Laurent Le Sage
- they're snobs--stuck-up and uppity and persnickety
• Syn:
bigheaded, persnickety, snooty, snot-nosed, snotty,
stuck-up, uppish
• Similar to:
proud
• Derivationally related forms:
uppishness (for: uppish), snot (for: snotty), snoot (for: snooty)