nosher
/ˈnɒʃə/(also nascha, nasher) informal
noun
A person who is fond of snacking or nibbling on food; a snacker; a diner. In early use: specifically a person who samples food before buying it.
Origin
Early 20th century; earliest use found in Jewish Child. Probably partly from Yiddish nasher (from Middle High German nascher, nescher (German Nascher, (now rare) Näscher) person with a sweet tooth from naschen, neschen to eat dainty food or delicacies + -er), and partly from nosh + -er.