A person who fails to act honestly or fulfills their commitments; someone who reneges on a deal.

धोखेबाज़

English Usage: "He is such a welch for not showing up to the meeting after agreeing to attend."

Hindi Usage: "वह बैठक में नहीं आया जबकि वह आने के लिए सहमत था, वह सचमुच एक धोखेबाज़ है।"

To cheat or defraud someone, especially in a gambling context.

धोखा देना

English Usage: "He tried to welch on the bet we made."

Hindi Usage: "उसने जो दांव हमने लगाया था, उस पर धोखा देने की कोशिश की।"