{adj. phr.}, {informal} Easy to get and so of little value; being an everyday thing because there are many of them; common. * /Mr. Jones gives A's to only one or two students, but in Mr. Smith's class, A's are a dime a dozen./
DIME A DOZEN
Meaning of DIME A DOZEN in English
Slang English vocab. Английский сленговый словарь. 2012