no mean

no mean (something)

Something considerably important, difficult, or noteworthy; something that is not trivial or easy to obtain. Defeating an incumbent president is no mean feat, but we feel confident that our candidate has what it takes. You should be proud! Placing in the top five at an Olympic event is no mean accomplishment.
See also: mean, no
Farlex Dictionary of Idioms.

no mean

INFORMAL
COMMON
1. You can use no mean before a word describing what someone does to show that someone does something well. She was no mean performer on a variety of other instruments. Moreover, Ramsay was no mean thinker himself.
2. You can use no mean before words like `achievement' or `task' to show that someone has done something difficult and deserves to be admired for it. To destroy 121 enemy aircraft is no mean record. Repton reached the final, and since around 1,500 schools entered the competition, that was no mean achievement.
See also: mean, no
Collins COBUILD Idioms Dictionary, 3rd ed.

no mean

— a very good —.
This expression was famously used by St Paul : ‘I am…a Jew of Tarsus…a citizen of no mean city’ (Acts 21:39).
1990 L.A. Style Surviving the rise and fall of art trends is no mean trick.
See also: mean, no
Farlex Partner Idioms Dictionary
See also:
  • (you) wanna make something of it?
  • a straw will show which way the wind blows
  • (you've) got to get up pretty early in the morning to (do something)
  • a horse of another
  • a horse of another color
  • a horse of another colour
  • (I) wouldn't (do something) if I were you
  • (do) (you) want to make something of it?
  • a/the feel of (something)
  • a crack at (someone or something)