brash
Rude and overly bold without thinking about others’ feelings.
Brash means bold and confident in a way that shows little concern for consequences or others' feelings. A brash person charges ahead without thinking things through, often coming across as rude or tactless even when they don't mean to be.
Picture a student who interrupts the teacher mid-sentence to announce they already know everything about the topic. That's brash behavior: confident, sure, but lacking the thoughtfulness to consider whether speaking up right then was wise or respectful. A brash comment might be honest but delivered without care for how it lands.
The word carries a hint of criticism. We admire confidence, but brashness suggests someone hasn't yet learned when to hold back. A brash young athlete might boast about winning before the game even starts, then struggle when their overconfidence meets reality. A brash decision gets made too quickly, without gathering enough information first.
Sometimes brashness fades with experience. That same athlete might later learn to let their performance speak for itself.