1. irresponsible; perfunctory; careless
いい加減なことばっかり言うなよ。Stop saying such irresponsible things.
2. lukewarm; half-baked; halfhearted; vague
3. (already) enough
used to express one's wish for something to end
いい加減、本当にもう帰ろうか。Honestly, it's about time we went home.
4. considerably; quite; rather; pretty
いい加減、腹も減ってきた。I'm getting pretty hungry, too.