The act of moving from one drinking establishment to another in a single outing, like climbing a ladder (はしご). Often used in social contexts.
See also: はしご酒
Let's go barhopping tonight.
We went to three places on our pub crawl.
Standard mixed kanji-kana spelling; the kanji 飲み is clear for 'drinking'.
Full kanji spelling using 梯子 for 'ladder'; less common and may be harder to read.
Compound of はしご (ladder) and 飲み (drinking), from the image of climbing a ladder from one bar to the next. The exact origin is uncertain, but it is a common modern expression.