To reduce, restrict, or limit one's budget or expenses; to live more modestly or make financial sacrifices. An allusion to having a thinner waistline due to having less to eat. It's pretty galling to see the CEO driving up to work in a brand new company car while the rest of us are being told to pull our belts in to help save the business money. With your mother out of work, we're all going to have to pull our belts in a notch for a little while. The new job pays less, so I've had to pull in my belt a notch or two, but I really love the work.