This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. A person who serves behind the counter in a coffee shop.

"There are so many things to make fun of at Starbucks: people talking on cell phones, annoying kids, the word barista, head lice, the fact there are thirty of you in line paying $3.50 for a cup of coffee while people are starving in Somalia."

coffee-maker    synthesiser