蹩腳 -

(of a person) incompetent; amateurish; (of a task or a skill) shoddy; unrefined; inferior

说蹩脚汉语 ― shuō biéjiǎo Hànyǔ ― to speak terrible Chinese

As in, 蹩脚货 “Limping foot goods” - shoddy quality stuff.

蹩腳 - Wiktionary, the free dictionary