Meaning:
“糊,” with the literal meaning of “overcooked,” is used by Chinese netizens jokingly to replace another character “胡” (hú, short form of “胡萝卜,” pronounced “húluóbo”). As the latter is the transliteration for the English word “flop,” “糊” is used to describe a celebrity that has faded out of the limelight. “咖,” pronounced similarly to the English word “casting,” has been used by Chinese netizens to refer to a certain type of personality, and used in terms such as “大咖” (dàkā, big shots). The term “糊咖” refers to actors or other entertainers, whose good luck has expired and are not popular or successful any more.
Example:
A: 最近有部剧挺接地气的，女主看着好眼熟但想不起来名字。
Zuìjìn yǒu bù jù tǐng jiēdìqì de，nǚzhǔ kànzhe hǎo yǎnshú dàn xiǎngbuqǐlái míngzì。
I’ve following a new show recently that’s quite true-to-life. The leading actress looks familiar but I can’t think of her name.
B: 国内这种演技还不错的糊咖挺多的。
Guónèi zhèzhǒng yǎnjì hái búcuò de húkā tǐng duō de。
Such actors abound in China, who know how to act but aren’t popular or successful.